build: Restrict binary compatibility to 2.14

On ELF systems, this bumps the soname from libxml2.so.2 to
libxml2.so.16. For historic reasons, the last component is the sum of
major and minor version.
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6a905e8..c9ca8d8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -412,7 +412,7 @@
 -Wno-long-long -Wno-format-extra-args -Wno-array-bounds")
 endif()
 
-set(LIBXML_MINOR_COMPAT 0)
+set(LIBXML_MINOR_COMPAT 14)
 math(EXPR LIBXML_SOVERSION "${LIBXML_MAJOR_VERSION} + ${LIBXML_MINOR_COMPAT}")
 set_target_properties(
     LibXml2
diff --git a/NEWS b/NEWS
index ef5c1be..dce7855 100644
--- a/NEWS
+++ b/NEWS
@@ -15,6 +15,9 @@
 option independently of XML Schemas support. It is still enabled by
 default.
 
+Binary compatibility is restricted to versions 2.14 or newer. On ELF
+systems, the soname was bumped from libxml2.so.2 to libxml2.so.16.
+
 ### New features
 
 Input callbacks can now be set on a parser context and an improved API
@@ -48,11 +51,13 @@
 was removed. The rest of the XPointer implementation isn't affected.
 The xpointer() scheme now behaves like the xpath1() scheme.
 
-Several legacy functions were removed from the header files.
+Several legacy symbols and the functions in xmlunicode.h were removed.
 
 The shell was moved from libxml2 to xmllint. Several related functions
 are no longer available.
 
+ELF version information was removed.
+
 ### Planned removals
 
 Support for HTTP is planned to be removed in the 2.15 release.
diff --git a/configure.ac b/configure.ac
index cb1aa6b..2b0e038 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,7 @@
 LIBXML_MICRO_VERSION_SUFFIX=
 
 # The oldest minor version we are compatible with.
-LIBXML_MINOR_COMPAT=0
+LIBXML_MINOR_COMPAT=14
 LIBXML_CURRENT=`expr $LIBXML_MAJOR_VERSION + $LIBXML_MINOR_VERSION`
 LIBXML_AGE=`expr $LIBXML_MINOR_VERSION - $LIBXML_MINOR_COMPAT`
 LIBXML_VERSION_INFO=$LIBXML_CURRENT:$LIBXML_MICRO_VERSION:$LIBXML_AGE
diff --git a/meson.build b/meson.build
index b55699d..01dc251 100644
--- a/meson.build
+++ b/meson.build
@@ -481,7 +481,7 @@
     endif
 endforeach
 
-v_min_compat = 0
+v_min_compat = 14
 xml_lib = library(
     'xml2',
     files(xml_src),