Reviewed by Chris.

    Reviewed by Chris.

        - WebKit part of fix for: <rdar://problem/3970670> Text context menu
          in WebKit needs "Look Up in Dictionary" item

        * WebView.subproj/WebDefaultContextMenuDelegate.m:
        (localizedMenuTitleFromAppKit):
        return English string in the case where AppKit bundle is found but doesn't
        contain the expected string. This case will be hit by people testing with
        an older AppKit.
        (-[WebDefaultUIDelegate menuItemWithTag:]):
        create Look Up in Dictionary item
        (-[WebDefaultUIDelegate contextMenuItemsForElement:]):
        add Look Up in Dictionary item and separator
        (-[WebDefaultUIDelegate editingContextMenuItemsForElement:]):
        ditto

        * WebView.subproj/WebHTMLView.m:
        (-[WebHTMLView _lookUpInDictionaryFromMenu:]):
        new method, handles bringing up the Dictionary window. Includes FIXMEs
        for a couple of the known loose ends.
        (-[WebHTMLView validateUserInterfaceItem:]):
        handle Look Up in Dictionary item like the other new items

        * WebView.subproj/WebUIDelegatePrivate.h:
        added SPI constant for Look Up in Dictionary menu item

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@8449 268f45cc-cd09-0410-ab3c-d52691b4dbfc