Prevent setSpeed function from using a value of 0 which actually means 'max speed' to a Dynamixel
Added 'set spd' option to arbotix_terminal
Added set_speed service to servo controller
Tweaked changes to speed control pull request based on comments from mikeferguson
Merge pull request #12 from pirobot/hydro-devel

Added speed control to arbotix_terminal and arbotix_python