(Baxter) Depth Sensor MoveIt! updates for Indigo

- Added Xtion depth sensor support (using openni_launch)
- Updated the Kinect launch dependency from openni to freenect for indigo
- Added rgb and depth frame parameters to remove leading '/' that tf2
  warned about in the console
- (aside) Updated the gitignore to ignore the warehouse directory that is auto-generated
Where did you put kinect? do you have any good parts that attach kinect to the robot? If this value differs for each robot, should we better to use rosparam to set the value?