A few platform specific tweaks

        * platform/cf/RetainPtr.h:
        (WebCore::RetainPtr::releaseRef): Fixed releaseRef to work with CF
        
        * platform/network/ResourceHandle.h: Added a "releaseRef" style call


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@20231 268f45cc-cd09-0410-ab3c-d52691b4dbfc