Add API to control OS X wxTextCtrl’s smart behavior

Allow the user to customize smart quotes and dashes substutions on OS X
and also provide the OSXDisableAllSmartSubstitutions() method for
disabling them all at once.

include/wx/osx/textctrl.h

@@ -130,6 +130,10 @@ public:
     virtual void MacSuperChangedPosition() wxOVERRIDE;
     virtual void MacCheckSpelling(bool check);
 
+    void OSXEnableAutomaticQuoteSubstitution(bool enable);
+    void OSXEnableAutomaticDashSubstitution(bool enable);
+    void OSXDisableAllSmartSubstitutions();
+
 protected:
     // common part of all ctors
     void Init();