[ros] Kuka interfaces

by Mirko D. Comparetti - fix #301
[builder] set_speed must be called first

component frequency is set relatively to the fps value - fix #311
[doc] fix public link s/ssh/git/ in mocap
[test] rename video_camera test for doc

video_camera_pgm_testing -> video_camera_testing for doc - fix #306
http://www.openrobots.org/morse/doc/stable/user/sensors/video_camera.html#other-sources-of-examples