Switch to relative includes.

Fixes #91.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2fbabf8..d9f4be8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.0)
-project(double-conversion VERSION 3.1.3)
+project(double-conversion VERSION 3.1.4)
 
 set(headers
     double-conversion/bignum.h
diff --git a/Changelog b/Changelog
index e80a722..943db26 100644
--- a/Changelog
+++ b/Changelog
@@ -1,18 +1,24 @@
+2019-03-11:
+  Use relative includes in the library. This shouldn't have any visible effect
+  for consumers of the library.
+
+  Update version number.
+
 2019-03-06:
-Fix typo in test.
-Update version number.
+  Fix typo in test.
+  Update version number.
 
 2019-03-03:
-Fix separator characters when they they don't fit into 8 bits.
-Update version number.
+  Fix separator characters when they they don't fit into 8 bits.
+  Update version number.
 
 2019-02-16:
-Check correctly for _MSC_VER.
-Patch by Ben Boeckel
+  Check correctly for _MSC_VER.
+  Patch by Ben Boeckel
 
 2019-01-17:
-Allow the library to be compiled for Emscripten.
-Patch by Tim Paine.
+  Allow the library to be compiled for Emscripten.
+  Patch by Tim Paine.
 
 2018-09-15:
   Update version numbers. This also updates the shared-library version number.
diff --git a/double-conversion/bignum-dtoa.cc b/double-conversion/bignum-dtoa.cc
index 526f96e..d99ac2a 100644
--- a/double-conversion/bignum-dtoa.cc
+++ b/double-conversion/bignum-dtoa.cc
@@ -27,10 +27,10 @@
 
 #include <cmath>
 
-#include <double-conversion/bignum-dtoa.h>
+#include "bignum-dtoa.h"
 
-#include <double-conversion/bignum.h>
-#include <double-conversion/ieee.h>
+#include "bignum.h"
+#include "ieee.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/bignum-dtoa.h b/double-conversion/bignum-dtoa.h
index 9d15ce3..34b9619 100644
--- a/double-conversion/bignum-dtoa.h
+++ b/double-conversion/bignum-dtoa.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_BIGNUM_DTOA_H_
 #define DOUBLE_CONVERSION_BIGNUM_DTOA_H_
 
-#include <double-conversion/utils.h>
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/bignum.cc b/double-conversion/bignum.cc
index a7bc86d..d077eef 100644
--- a/double-conversion/bignum.cc
+++ b/double-conversion/bignum.cc
@@ -25,8 +25,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#include <double-conversion/bignum.h>
-#include <double-conversion/utils.h>
+#include "bignum.h"
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/bignum.h b/double-conversion/bignum.h
index 238a351..7c289fa 100644
--- a/double-conversion/bignum.h
+++ b/double-conversion/bignum.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_BIGNUM_H_
 #define DOUBLE_CONVERSION_BIGNUM_H_
 
-#include <double-conversion/utils.h>
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/cached-powers.cc b/double-conversion/cached-powers.cc
index 6f771e9..8ab281a 100644
--- a/double-conversion/cached-powers.cc
+++ b/double-conversion/cached-powers.cc
@@ -29,9 +29,9 @@
 #include <cmath>
 #include <cstdarg>
 
-#include <double-conversion/utils.h>
+#include "utils.h"
 
-#include <double-conversion/cached-powers.h>
+#include "cached-powers.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/cached-powers.h b/double-conversion/cached-powers.h
index eabff4a..61a5061 100644
--- a/double-conversion/cached-powers.h
+++ b/double-conversion/cached-powers.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_CACHED_POWERS_H_
 #define DOUBLE_CONVERSION_CACHED_POWERS_H_
 
-#include <double-conversion/diy-fp.h>
+#include "diy-fp.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/diy-fp.cc b/double-conversion/diy-fp.cc
index 82b0d08..ddd1891 100644
--- a/double-conversion/diy-fp.cc
+++ b/double-conversion/diy-fp.cc
@@ -26,8 +26,8 @@
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
-#include <double-conversion/diy-fp.h>
-#include <double-conversion/utils.h>
+#include "diy-fp.h"
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/diy-fp.h b/double-conversion/diy-fp.h
index e2011d4..2edf346 100644
--- a/double-conversion/diy-fp.h
+++ b/double-conversion/diy-fp.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_DIY_FP_H_
 #define DOUBLE_CONVERSION_DIY_FP_H_
 
-#include <double-conversion/utils.h>
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/double-conversion.cc b/double-conversion/double-conversion.cc
index 388cb39..d5a04f6 100644
--- a/double-conversion/double-conversion.cc
+++ b/double-conversion/double-conversion.cc
@@ -29,14 +29,14 @@
 #include <locale>
 #include <cmath>
 
-#include <double-conversion/double-conversion.h>
+#include "double-conversion.h"
 
-#include <double-conversion/bignum-dtoa.h>
-#include <double-conversion/fast-dtoa.h>
-#include <double-conversion/fixed-dtoa.h>
-#include <double-conversion/ieee.h>
-#include <double-conversion/strtod.h>
-#include <double-conversion/utils.h>
+#include "bignum-dtoa.h"
+#include "fast-dtoa.h"
+#include "fixed-dtoa.h"
+#include "ieee.h"
+#include "strtod.h"
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/double-conversion.h b/double-conversion/double-conversion.h
index 7495d17..6dbc099 100644
--- a/double-conversion/double-conversion.h
+++ b/double-conversion/double-conversion.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_DOUBLE_CONVERSION_H_
 #define DOUBLE_CONVERSION_DOUBLE_CONVERSION_H_
 
-#include <double-conversion/utils.h>
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/fast-dtoa.cc b/double-conversion/fast-dtoa.cc
index e5c2222..6135038 100644
--- a/double-conversion/fast-dtoa.cc
+++ b/double-conversion/fast-dtoa.cc
@@ -25,11 +25,11 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-#include <double-conversion/fast-dtoa.h>
+#include "fast-dtoa.h"
 
-#include <double-conversion/cached-powers.h>
-#include <double-conversion/diy-fp.h>
-#include <double-conversion/ieee.h>
+#include "cached-powers.h"
+#include "diy-fp.h"
+#include "ieee.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/fast-dtoa.h b/double-conversion/fast-dtoa.h
index ac4317c..5f1e8ee 100644
--- a/double-conversion/fast-dtoa.h
+++ b/double-conversion/fast-dtoa.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_FAST_DTOA_H_
 #define DOUBLE_CONVERSION_FAST_DTOA_H_
 
-#include <double-conversion/utils.h>
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/fixed-dtoa.cc b/double-conversion/fixed-dtoa.cc
index 8c111ac..0f989bc 100644
--- a/double-conversion/fixed-dtoa.cc
+++ b/double-conversion/fixed-dtoa.cc
@@ -27,8 +27,8 @@
 
 #include <cmath>
 
-#include <double-conversion/fixed-dtoa.h>
-#include <double-conversion/ieee.h>
+#include "fixed-dtoa.h"
+#include "ieee.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/fixed-dtoa.h b/double-conversion/fixed-dtoa.h
index a9436fc..3bdd08e 100644
--- a/double-conversion/fixed-dtoa.h
+++ b/double-conversion/fixed-dtoa.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_FIXED_DTOA_H_
 #define DOUBLE_CONVERSION_FIXED_DTOA_H_
 
-#include <double-conversion/utils.h>
+#include "utils.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/ieee.h b/double-conversion/ieee.h
index baaeced..4a5fe8f 100644
--- a/double-conversion/ieee.h
+++ b/double-conversion/ieee.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_DOUBLE_H_
 #define DOUBLE_CONVERSION_DOUBLE_H_
 
-#include <double-conversion/diy-fp.h>
+#include "diy-fp.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/strtod.cc b/double-conversion/strtod.cc
index e8cc13f..a75cf5d 100644
--- a/double-conversion/strtod.cc
+++ b/double-conversion/strtod.cc
@@ -28,10 +28,10 @@
 #include <climits>
 #include <cstdarg>
 
-#include <double-conversion/bignum.h>
-#include <double-conversion/cached-powers.h>
-#include <double-conversion/ieee.h>
-#include <double-conversion/strtod.h>
+#include "bignum.h"
+#include "cached-powers.h"
+#include "ieee.h"
+#include "strtod.h"
 
 namespace double_conversion {
 
diff --git a/double-conversion/strtod.h b/double-conversion/strtod.h
index 3226516..ed0293b 100644
--- a/double-conversion/strtod.h
+++ b/double-conversion/strtod.h
@@ -28,7 +28,7 @@
 #ifndef DOUBLE_CONVERSION_STRTOD_H_
 #define DOUBLE_CONVERSION_STRTOD_H_
 
-#include <double-conversion/utils.h>
+#include "utils.h"
 
 namespace double_conversion {