added the static function GetLabelText() to wxStaticText which was mentioned in the docs but not implemented; also fixed the return type documented for wxControl::GetLabel*() functions

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@47880 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/stattext.h

@@ -58,6 +58,9 @@ public:
 
     // public utilities (symmetric to those in wxControl about mnemonics):
 
+    // get the string without mnemonic characters ('&') and without markup
+    static wxString GetLabelText(const wxString& label);
+
     // removes the markup accepted by wxStaticText when wxST_MARKUP is used,
     // and then returns the cleaned string
     static wxString RemoveMarkup(const wxString& str);