[connectionagent] Don't automatically turn on tech power.

If the user has explicitly turned the power off for a particular
technology don't turn it back on. Instead fail and and emit
configurationNeeded() which will trigger the system connection
selector dialog.
Merge pull request #59 from lpotter/master

dont connect when autoconnect is toggled if network is already connected
bump version to 0.11.1
Merge pull request #60 from amccarthy/master

[connectionagent] Don't automatically turn on tech power.
Bump version to 0.11.2
[connectionagent] make connectToType work correctly.

If type is already connected, don't popup dialog.