miscellaneous wxFont enhancements (patch 1496606):

- made SetFaceName() bool and return false if the face name is not available
- corrected To/FromUserString() to complement each other


git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@39411 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/fontenum.h

@@ -67,6 +67,10 @@ public:
     // convenience function that returns array of all available encodings.
     static wxArrayString GetEncodings(const wxString& facename = wxEmptyString);
 
+    // convenience function that returns true if the given face name exist
+    // in the user's system
+    static bool IsValidFacename(const wxString &str);
+
 private:
     DECLARE_NO_COPY_CLASS(wxFontEnumerator)
 };