[Runtime] Add support to query application running status for service mode.

On Tizen WRT, "wrt-launcher -r $appid" is for checking the status of app
laucher, "running" or "not running". But on Crosswalk, there is no
command for checking status of app launcher.

This PR is to implement above feature.

BUG=XWALK-1133
Merge pull request #1740 from shaochangbin/check-running-support

[Runtime] Add support to query application running status for service mode.