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
Merge commit '604b9e0' into gazebo-activity

Conflicts:
	rtt_gazebo_plugin/package.xml
gazebo_rtt_plugin: fixed find_package(orocos_kdl)
Merge branch 'orocos_kdl-find-package-fixes' into gazebo-activity
gazebo_activity: added header install rule
rtt_gazebo_activity: added build and run dependency to rtt_rosgraph_msgs
Merging changes from gazebo-activity branch, and fixing some KDL resolution problems