[connectionagent] Fix contention between manual connections and autoconnections.

When manually connecting to a service connection agent will respond to
the previously connected service going to the 'idle' state by
performing an autoconnect, which can trigger the connection to the
manually service to abort and the connection restored to the previous
service.
[connectionagent] Fix incorrect conversion of false to QString().

Quiet compile warnings.
Merge pull request #37 from amccarthy/master

Fix contention between manual connection and autoconnect