Auto-generate the ChangeLog from the git log for 'make dist'.

	* Makefile.am: Include the dist-changelog.am file copied in build/
	from mm-common so that the ChangeLog is automatically generated from
	the git commit messages on 'make dist'.
Move to a generated ChangeLog.
clutter_methods.defs updated.

h2def.py run against clutter-1.7.6 to generate the file.
clutter_enums.defs updated to clutter-1.7.6

enum.pl run against the clutter-1.7.6 release.