[Qt] style-police, add missing license headers

- add missing license headers in Mac files
- small code formating cleanups

src/qt/macnotificationhandler.mm

@@ -1,3 +1,7 @@
+// Copyright (c) 2011-2013 The Bitcoin Core developers
+// Distributed under the MIT/X11 software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
 #include "macnotificationhandler.h"
 
 #undef slots