Added OS/2 patches to wxGTK.

Updated docs.
  Added wxMask code.
  Added Sylvain's newest tree ctrl code and sample.
  Corrected wxDC background colour (now as wrong as wxMSW).


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@2767 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/confbase.h

@@ -246,11 +246,11 @@ public:
 
 protected:
   static bool IsImmutable(const wxString& key)
-  #ifndef __WXMAC__
+#if !defined(__WXMAC__) && !defined(__EMX__)
     { return !key.IsEmpty() && key[0u] == wxCONFIG_IMMUTABLE_PREFIX; }
-  #else
+#else
     { return !key.IsEmpty() && key[0ul] == wxCONFIG_IMMUTABLE_PREFIX; }
-  #endif
+#endif
 
 private:
   // are we doing automatic environment variable expansion?