Add mising roscpp dependency.
Add missing explicit header dependency.

Don't get required header transitively, but explicitly.
Enforcing i_min_ <= 0 and i_max_ >= 0 in integral bound parameters, reducing duplicated code
Merge branch 'master' of github.com:willowgarage/ros_control
Merge pull request #20 from pal-robotics/master

Minor missing header and ROS package dependencies
Merge pull request #21 from jbohren-forks/fix-safe-integral-bound-params

Enforcing 0.0 \in [i_min_, i_max_] in PID integral bound parameters, reducing duplicated code