Reviewed by Dave Hyatt.

        Add a new WebNetscapePluginStream C++ class. The idea is that it is supposed to replace the Obj-C 
        WebBaseNetscapePluginStream class. The plan is to gradually move/rewrite code from the Obj-C class to the C++ class
        until the C++ class can replace the Obj-C class.
        
        * Plugins/WebBaseNetscapePluginStream.h:
        (WebNetscapePluginStream::create):
        (WebNetscapePluginStream::WebNetscapePluginStream):
        * Plugins/WebBaseNetscapePluginStream.mm:
        (-[WebBaseNetscapePluginStream initWithFrameLoader:]):
        (-[WebBaseNetscapePluginStream initWithRequest:plugin:notifyData:sendNotification:]):
        (-[WebBaseNetscapePluginStream dealloc]):
        (-[WebBaseNetscapePluginStream finalize]):



git-svn-id: http://svn.webkit.org/repository/webkit/trunk@36497 268f45cc-cd09-0410-ab3c-d52691b4dbfc