Update for 2.1.6

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
diff --git a/RELEASE b/RELEASE
index cd57a8b..399088b 100644
--- a/RELEASE
+++ b/RELEASE
@@ -1 +1 @@
-2.1.5
+2.1.6
diff --git a/VERSION b/VERSION
index cd57a8b..399088b 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-2.1.5
+2.1.6
diff --git a/doc/Doxyfile b/doc/Doxyfile
index be5e534..ae45600 100644
--- a/doc/Doxyfile
+++ b/doc/Doxyfile
@@ -31,7 +31,7 @@
 # This could be handy for archiving the generated documentation or
 # if some version control system is used.
 
-PROJECT_NUMBER         = 2.1.5
+PROJECT_NUMBER         = 2.1.6
 
 # With the PROJECT_LOGO tag one can specify a logo or icon that is included
 # in the documentation. The maximum height of the logo should not exceed 55