Fix typos in comments

Comments contained some typos. Comments have been replaced with
the ‘official’ description from
http://msdn.microsoft.com/en-us/library/8x5x43k7.aspx.

Change-Id: I25dda0911735b4a0d4f306bc95bc984be0080e2f
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>
Mac: Remove old unified toolbar implementation.

This has been dead code in Qt 5 since WS_MAC isn't
defined any more.

The new implementation is far less intrusive and does
not require a separate layout.

Task-number: QTBUG-34411
Change-Id: I91bf2294086cb7334a0f56eb1bb97464d8d7b2e3
Reviewed-by: Gabriel de Dietrich <gabriel.dedietrich@digia.com>