Remove wxMGL port.

The company behind MGL toolkit (SciTech) doesn't exist since several years and
this port is not used by anybody, so remove it to ease maintenance burden.


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@70353 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/defs.h

@@ -40,7 +40,6 @@
          !defined(__WXOSX_IPHONE__)   && \
          !defined(__WXCOCOA__) && \
          !defined(__X__)       && \
-         !defined(__WXMGL__)   && \
          !defined(__WXDFB__)   && \
          !defined(__WXX11__)   && \
           wxUSE_GUI
@@ -3277,10 +3276,6 @@ typedef struct _PangoLayout          PangoLayout;
 typedef struct _PangoFontDescription PangoFontDescription;
 #endif
 
-#ifdef __WXMGL__
-typedef struct window_t *WXWidget;
-#endif /*  MGL */
-
 #ifdef __WXDFB__
 /* DirectFB doesn't have the concept of non-TLW window, so use
    something arbitrary */