Call glib-compile-schemas correctly in install scripts

The glib-compile-schemas command needs to be called on post_install, post_upgrade and post_remove. Clean up empty functions.
More fixes in install scripts
Merge pull request #110 from City-busz/install-fixes

Call glib-compile-schemas correctly in install scripts
All patching now happens in prepare()
All packages cleaned up as per TU recommendations.
All packages cleaned up as per TU recommendations.