Merge pull request #50 from jfallows/develop

Add BBOSH server bootstrap (polling strategy) ...
Candidate fix for issue #55 NPE in LocationInfo at end of test.

Appears that a null LocationInfo is making it into the ArrayList of LocationInfos, despite a null check guard.
Expect this is caused by a multi-threaded race between client worker and server worker during test teardown.
Updated relevant data structures to their concurrent equivalents.