Reviewed by Adam.

        Primarily, this patch implements/hooks-up actions for the sub-menu
        items in WebCore context menus. I fixed a few other things along
        the way too:
                -Made BUILDING_ON_TIGER ifdef work within C++ as well as
                 Obj-C
                -Fixed bug where we would throw and Obj-C exception and
                 fail to pop up menus with more than one separator item.
                -Re-named some of the spelling/grammar tags since Tiger and
                 Leopard share more of the actions than initially
                 anticipated.

        * WebCorePrefix.h: Make BUILDING_ON_TIGER available to C++
        * bridge/EditorClient.h: New functions to toggle
        spelling/grammar checking.
        * editing/Editor.cpp:
        (WebCore::Editor::toggleContinuousSpellChecking): Call into client.
        (WebCore::Editor::toggleGrammarChecking): Same.
        (WebCore::Editor::toggleBold): call execToggleBold()
        (WebCore::Editor::toggleUnderline): Create appropriate underline
        style and apply to selection.
        (WebCore::Editor::setBaseWritingDirection): Create appropriate
        writing direction and apply to selection.
        * editing/Editor.h:
        * editing/mac/EditorMac.mm: New functions to show spelling guesses,
        fonts, styles, and color panels.
        * page/ContextMenuClient.h: New functions for the speech sub-menu.
        * page/ContextMenuController.cpp:
        (WebCore::ContextMenuController::contextMenuItemSelected): Fill in
        editing sub-menu actions.
        * platform/ContextMenu.cpp:
        (WebCore::separatorItem): Helper function to create a separator 
        item.
        (WebCore::createFontSubMenu): Put very mac-specific things within a
        platform ifdef.
        (WebCore::createSpellingAndGrammarSubMenu): Re-named some of the
        spelling sub-menu tags.
        (WebCore::createSpellingSubMenu): Same.
        (WebCore::ContextMenu::populate): We can't share the separator
        item. When we do, menus with more than one separator throw and obj-
        c exception and fail to pop-up.
        * platform/ContextMenuItem.h:
        (WebCore::): Re-named some of the spelling sub-menu tags.

WebKit:
        Reviewed by Adam.

        WebKit support for editing sub-menu actions.

        * WebCoreSupport/WebContextMenuClient.h: New functions for the
        speech sub-menu.
        * WebCoreSupport/WebContextMenuClient.mm:
        (WebContextMenuClient::speak):
        (WebContextMenuClient::stopSpeaking):
        * WebCoreSupport/WebEditorClient.h: New functions to toggle
        spelling/grammar checking.
        * WebCoreSupport/WebEditorClient.mm:
        (WebEditorClient::toggleContinuousSpellChecking):
        (WebEditorClient::toggleGrammarChecking):
        * WebView/WebUIDelegatePrivate.h: Re-named some of the spelling
        sub-menu tags.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@18166 268f45cc-cd09-0410-ab3c-d52691b4dbfc