[GTK] Should provide an API to control the IconDatabase
        https://bugs.webkit.org/show_bug.cgi?id=32334

        First step towards a full IconDatabase API. This provides
        notification for pages with favicons, and lets clients handle
        them.

        * WebCoreSupport/FrameLoaderClientGtk.cpp:
        (WebKit::FrameLoaderClient::registerForIconNotification):
        (WebKit::FrameLoaderClient::dispatchDidReceiveIcon):
        * tests/resources/blank.ico: Added.
        * tests/testwebview.c: Added.
        (server_callback):
        (idle_quit_loop_cb):
        (icon_uri_changed_cb):
        (icon_loaded_cb):
        (test_webkit_web_view_icon_uri):
        (main):
        * webkit/webkitprivate.cpp:
        (closeIconDatabaseOnExit):
        (webkit_init):
        * webkit/webkitprivate.h:
        * webkit/webkitwebview.cpp:
        (webkit_web_view_get_property):
        (webkit_web_view_finalize):
        (webkit_web_view_class_init):
        (webkit_web_view_get_icon_uri):
        * webkit/webkitwebview.h:

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@51948 268f45cc-cd09-0410-ab3c-d52691b4dbfc