added a method to get the controller state topic for a given joint. The test passes fine if you start gazebo individually but fails when running make test (gazebo is killed before the service has had time to be interrogated...
Merge branch 'development' of github.com:shadow-robot/sr-ros-interface into F_hand_cmdr_get_state_topic

Conflicts:
	sr_hand/include/sr_hand/hand_commander.hpp
	sr_hand/src/hand_commander.cpp
	sr_hand/test/hand_commander_test.cpp
	sr_hand/test/hand_commander_test.launch
added sleep for gazebo test to succeed
Merge branch 'development' into F_hand_cmdr_get_state_topic
added negative state here as well, ie what happens when we pass an unknown joint name. Inspection suggests we get an empty string.
Merge pull request #3 from shadow-robot/F_hand_cmdr_get_state_topic

Added a method to get the topic for the controller state callback.