[GTK] Build fixes after 145552
https://bugs.webkit.org/show_bug.cgi?id=112267

Patch by Zan Dobersek <zdobersek@igalia.com> on 2013-03-13
Reviewed by Gustavo Noronha Silva.

Source/Platform:

* GNUmakefile.am: Include the same-level GNUmakefile.list.am.
Fix a typo in the inline visibility compiler flag.

Source/WebKit2:

* GNUmakefile.am: Narrow down the dependency CFLAGS list to only ones that are actually needed
to build the platformgtk_sources into libPlatformGtk2.la. At the moment this means only
GTK+-2.0 CFLAGS are used.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@145738 268f45cc-cd09-0410-ab3c-d52691b4dbfc