[connman-qt] Expose functionality required to reset counters.

Add NetworkService::resetCounters() function.
Merge pull request #48 from lpotter/master

revert async change
Merge pull request #46 from amccarthy/fixes

[connman-qt] Expose functionality required to reset counters.
[connman-qt] bump version to 1.0.17
[connman-qt] set delayedReply on request dbus message.

only start timer if not active.