Merge branch 'accel_key_compat' of https://github.com/imciner2/wxWidgets

Give warnings for accelerator keys not supported by GTK under all
platforms instead of using asserts fin wxGTK only.

See https://github.com/wxWidgets/wxWidgets/pull/1505

include/wx/accel.h

@@ -53,7 +53,9 @@ public:
         , m_keyCode(keyCode)
         , m_command(cmd)
         , m_item(item)
-        { }
+    {
+        ValidateKey(flags, keyCode);
+    }
 
     // create accelerator corresponding to the specified string, return NULL if
     // string couldn't be parsed or a pointer to be deleted by the caller
@@ -61,6 +63,8 @@ public:
 
     void Set(int flags, int keyCode, int cmd, wxMenuItem *item = NULL)
     {
+        ValidateKey(flags, keyCode);
+
         m_flags = flags;
         m_keyCode = keyCode;
         m_command = cmd;
@@ -118,6 +122,8 @@ public:
 private:
     wxString AsPossiblyLocalizedString(bool localized) const;
 
+    static bool ValidateKey(int flags, int keycode);
+
     // common part of Create() and FromString()
     static bool ParseAccel(const wxString& str, int *flags, int *keycode);