Added wxUSE_DC_CACHEING and associated code to wxMSW

Added EnableCache, CacheEnabled to wxDCBase
Added mask source args to DoBlit, Blit
Added cache testing code to dragimag sample
Added wxSystemOptions, regenerated makefiles


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@10962 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/mac/dc.h

@@ -213,7 +213,7 @@ protected:
 
     virtual bool DoBlit(wxCoord xdest, wxCoord ydest, wxCoord width, wxCoord height,
                         wxDC *source, wxCoord xsrc, wxCoord ysrc,
-                        int rop = wxCOPY, bool useMask = FALSE);
+                        int rop = wxCOPY, bool useMask = FALSE, wxCoord xsrcMask = -1, wxCoord ysrcMask = -1);
 
     // this is gnarly - we can't even call this function DoSetClippingRegion()
     // because of virtual function hiding