Fix arbitrary numeric weights in the generic wxNativeFontInfo

Store the weight as int, not wxFontWeight, and rely on the same wrappers
as all the other ports in the port not having native wxNativeFontInfo.

This is a prerequisite for fixing wxDFB and other Unix ports not using
Pango.

include/wx/fontutil.h

@@ -188,7 +188,7 @@ public :
     float         pointSize;
     wxFontFamily  family;
     wxFontStyle   style;
-    wxFontWeight  weight;
+    int           weight;
     bool          underlined;
     bool          strikethrough;
     wxString      faceName;
@@ -229,7 +229,7 @@ public:
 #else
         // translate all font parameters
         SetStyle((wxFontStyle)font.GetStyle());
-        SetWeight((wxFontWeight)font.GetWeight());
+        SetNumericWeight(font.GetNumericWeight());
         SetUnderlined(font.GetUnderlined());
         SetStrikethrough(font.GetStrikethrough());
 #if defined(__WXMSW__)