Added remote gateway connection statistics to message
Merge pull request #31 from piyushk/establish_connection_statistics

Added remote gateway connection statistics to message
invitation error handling feedback.
added time since last seen when a gateway is unavailable
Merge branch 'hydro-devel' of https://github.com/robotics-in-concert/rocon_msgs into establish_connection_statistics
added time_since_last_seen if gateway is down
Merge pull request #32 from piyushk/establish_connection_statistics

Establish connection statistics