cr-string: Prevent memory leak

Instead of leaking the existing GString, truncate and append to it
instead.

https://bugzilla.gnome.org/show_bug.cgi?id=678736
cr-om-parser: Stop memory leak

The parser refs the doc handler, so we need to unref it here.

https://bugzilla.gnome.org/show_bug.cgi?id=678736
Version 0.6.6
Post release version bump
Revert "cr-rgb: Fix mapping for 'green'"

This reverts commit 0cbb0dfed7350ed48a12d56925cdd76255891aa5.

This violates the CSS and SVG standards.

https://bugzilla.gnome.org/show_bug.cgi?id=685679
build: Fix include directive

https://bugzilla.gnome.org/show_bug.cgi?id=686126
Version 0.6.7
Post release version bump
cr-tknzr: Handle signed units

Parse something like '-20px' correctly.

https://bugzilla.gnome.org/show_bug.cgi?id=686239
Version 0.6.8
Post release version bump
build: add support for automake 1.13

In Automake 1.13, the long-deprecated macro AM_CONFIG_HEADER (deprecated
since 2002) has been removed in favour of AC_CONFIG_HEADERS.

Bug #692111.
build: rename configure.in into configure.ac

With the upcoming version of automake (1.14) the support
for the configure.in file will be dropped.[1]

[1]http://lists.gnu.org/archive/html/automake/2012-12/msg00038.html

Bug #692111.