Remove support for wxMotif

This port hasn't been updated for ages and is not used by anybody any
longer, so remove its code to facilitate maintenance.

Also remove references to this port from the documentation and most of
the other places (VMS-specific descrip.vms files still check for it
because it's not clear how to update them all), including configure.

Regenerate the latter and rebake all makefiles.

Finally document that this port is not available any longer.

include/wx/defs.h

@@ -48,8 +48,7 @@
 /*  Make sure the environment is set correctly */
 #   if defined(__WXMSW__) && defined(__X__)
 #       error "Target can't be both X and MSW"
-#   elif !defined(__WXMOTIF__) && \
-         !defined(__WXMSW__)   && \
+#   elif !defined(__WXMSW__)   && \
          !defined(__WXGTK__)   && \
          !defined(__WXOSX_COCOA__)   && \
          !defined(__WXOSX_IPHONE__)   && \
@@ -1461,16 +1460,8 @@ wxALLOW_COMBINING_ENUMS(wxSizerFlagBits, wxStretch)
 /*  Windows, it won't normally get the dialog navigation key events) */
 #define wxWANTS_CHARS           0x00040000
 
-/*  Make window retained (Motif only, see src/generic/scrolwing.cpp)
- *  This is non-zero only under wxMotif, to avoid a clash with wxPOPUP_WINDOW
- *  on other platforms
- */
-
-#ifdef __WXMOTIF__
-#define wxRETAINED              0x00020000
-#else
+/*  Deprecated, defined only for compatibility. */
 #define wxRETAINED              0x00000000
-#endif
 #define wxBACKINGSTORE          wxRETAINED
 
 /*  set this flag to create a special popup window: it will be always shown on */
@@ -2931,8 +2922,8 @@ typedef WXLRESULT (wxSTDCALL *WXWNDPROC)(WXHWND, WXUINT, WXWPARAM, WXLPARAM);
 #endif /*  __WIN32__ */
 
 
-#if defined(__WXMOTIF__) || defined(__WXX11__)
-/* Stand-ins for X/Xt/Motif types */
+#if defined(__WXX11__)
+/* Stand-ins for X/Xt types */
 typedef void*           WXWindow;
 typedef void*           WXWidget;
 typedef void*           WXAppContext;
@@ -2955,9 +2946,9 @@ typedef void*           WXFontType; /* either a XmFontList or XmRenderTable */
 typedef void*           WXString;
 
 typedef unsigned long   Atom;  /* this might fail on a few architectures */
-typedef long            WXPixel; /* safety catch in src/motif/colour.cpp */
+typedef long            WXPixel;
 
-#endif /*  Motif */
+#endif /* X11 */
 
 #ifdef __WXGTK__