Linux/gdk build fixes.

        * Projects/gdk/webcore-gdk.bkl: Account for file renaming.
        * platform/gdk/KeyEventGdk.cpp: Make gdk's tab key recognized as tab so that
        keyboard link walking works on gdk.
        (WebCore::keyIdentifierForGdkKeyCode):


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@19523 268f45cc-cd09-0410-ab3c-d52691b4dbfc