[connman] allow user input request signal when using autoconnect.

If passphrase gets changed, it needs to pass on the user Input request
signal to clients to be able to re-autoconnect.
[connman] try connecting to failure state service.

Tries at least once regardless, if there still is invalid-key error,
send User Input Requested via agent. If user cancels that request,
stop trying to connect.

This helps when a wireless AP with same ssid/enc but unknown
comes within range. connman issues an invalid-key, as the passwords
are different. Which would cause connman to not try and connect when the
good, known AP comes within range.
[connman] fix crash and report error properly.
Merge pull request #68 from lpotter/master

[connman] allow user input request signal when using autoconnect.