Allow the QLocalServer to listen to a native descriptor

Allow the QLocalServer to listen to a native descriptor

QLocalServer could only listen to sockets it created.
Thi is not always possible as sockets may be passed
by socketpair() or have to be created locally by
other means.  This adds a similar feature to QLocalSocket
where a native descriptor maybe used.

Change-Id: I43b0af179b3b868dd164d4e1fd312ff4546cf9ff
Reviewed-by: Michalina Ziemba <michalina.ziemba@nokia.com>
Reviewed-by: Tapani Mikola <tapani.mikola@nokia.com>
Reviewed-by: Harald Fernengel <harald.fernengel@nokia.com>