[connectionagent] fix a bug where only reboot helps.

Sometimes, this would get into wonky state where currentNetworkState
was stuck in association and could not be cleared.
[connectionagent] fix bug where mobile data would make itself
autoconnectable, when wlan and mobile data were switched off at
about the same time.

mobile data would be in the connection state due to autoconnect,
so the autoconnect to false would not work.

This seems to work for 99% of the time, but will still fail if the
timing is right.
Merge pull request #55 from lpotter/master

fix a few bugs