Merge pull request #32 from mitchellwills/master

Cleanup
Added walrus_bringup package
Added walrus_description package with old calf model
Created walrus_contorl package
First pass at a gazebo WALRUS gazebo plugin
Added gazebo construction world
Did some cleanup and commenting of new controls stuff
Did a little cleanup and fixed dependancies
Created walrus_base_hw package and template node
updated package dependancies
Updated travis to build ros_control again because we now depend on changes only in indigo
Removed unneeded urdf include
Cleaned up tf namespacing
Began adding boom to robot model
Added kinect sensor
Added controllers for boom motors
Added IMU to gazebo model