task #47619: Defer calls to OutputStreams in GaudiMP

Added the algorithms implementing the deferred write and added
a minimal test.

https://savannah.cern.ch/task/index.php?47619

From: Marco Clemencic <marco.clemencic@cern.ch>


git-svn-id: file:///afs/cern.ch/work/b/binet/dev/repos/gaudi-svn-mirror/Gaudi/trunk/GaudiMP@7320 22b0f739-a4da-4a50-9948-337547c35a65