Make QBasicMutex be exclusively non-recursive

Make QBasicMutex be exclusively non-recursive

Dispatch to the recursive mutex functions from QMutex::lock, tryLock
and unlock.

This has the benefit that those using QBasicMutex will not go through
the testing for recursive mutexes. It simplifies a little the code for
those users.

For the users of QMutex, the code required to perform a lock does not
appear to change.

Change-Id: I0ca9965e012b283c30f1fab8e9f6d9b3288c2247
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>