Changing datatransfer implementation from CFPasteboard to NSPasteboard API (#1264)

* changing datatransfer from CFPasteboard to NSPasteboard API

* factoring and cleaning up

* Switching back naming

* missed file

* getting wxCFStringRef to be independent of system headers

* add unichar include

* using wxCFStringRef in header

* moving to private headers, change method name

* adapting to lesser content in cfstring.h

* Removing malloc/free usage

* use wxScopedArray throughout

* using wxMemoryBuffer instead of char[]

* fixing nonprecomp headers

* missing forward decl in non-precomp builds

include/wx/osx/core/private/strconv_cf.h

@@ -13,6 +13,7 @@
 
 #include <CoreFoundation/CFString.h>
 #include <CoreFoundation/CFStringEncodingExt.h>
+#include "wx/fontmap.h"
 
 // ============================================================================
 // CoreFoundation conversion classes
@@ -335,3 +336,20 @@ private:
     CFStringEncoding m_encoding ;
 };
 
+// corresponding class for holding UniChars (native unicode characters)
+
+class WXDLLIMPEXP_BASE wxMacUniCharBuffer
+{
+    public :
+    wxMacUniCharBuffer( const wxString &str ) ;
+
+    ~wxMacUniCharBuffer() ;
+
+    UniCharPtr GetBuffer() ;
+
+    UniCharCount GetChars() ;
+
+    private :
+    UniCharPtr m_ubuf ;
+    UniCharCount m_chars ;
+};