[GTK] Disable support for unprefixed CSS animations, transitions, transforms in release builds
https://bugs.webkit.org/show_bug.cgi?id=107436

Reviewed by Alexis Menard.

Disable the unprefixed CSS animations, transitions and transforms support
in the release builds for now. The work in this area is not yet complete
and should not ship in such state.

No new tests - no new functionality.

* GNUmakefile.features.am.in:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140407 268f45cc-cd09-0410-ab3c-d52691b4dbfc