rtt_gazebo_activity: added GazeboActivity that gets triggered by RTTSystem::clockUpdate()
rtt_gazebo_activity: added gazebo service
rtt_gazebo_activity: only use gazebo time if /use_sim_time parameter is set to true
rtt_gazebo_activity: added missing dependency to roscpp
rtt_gazebo_activity: reset the Logger's reference time when switching to Gazebo time
gazebo_activity: added header install rule
rtt_gazebo_activity: added build and run dependency to rtt_rosgraph_msgs
Merging in changes from @meyerj
Merge branch 'master' of github.com:jhu-lcsr/rtt_gazebo