Fix commands compatability with RB 1.6.x

Review Request #3884 — Created Feb. 18, 2013 and submitted — Latest diff uploaded

Information

RBTools
master

Reviewers

Fix commands compatability with RB 1.6.x

Review Board 1.6.x does not provide a 'capabilities' field in the info
resource which causes commands requiring it to fail. We now default
the capabilities to be empty if they can't be found on the server.
Posted code before and after the fix to a 1.6.x server and confirmed
the expected behaviour.