added NS_ERROR_NO_AGGREATION to widget factory. marked code with XXX where
additional work is required. Removed unused global variables in nsWindow.cpp
creator of prescontext is responsible for initializing pres context.
devicecontext is now init()ed with a nsNativeWidget.
removed hacky X Display stuff from device context and font metrics.
removed hacky code from windows font metrics.
changed nsNativeWindow to be nsNativeWidget.
added more code for compositor back-to-front pass.
improved text performance on X.
changed nsHTMLTagContent.cpp so that it will build with MSVC 4.1.