Remove autogenerated files

Over at sigproc/robotic_surgery#9, we've started using this package as part of a Masters project in Engineering. @Somahtr and myself catkin-ized the package but that's not what this PR is about. In the process of integrating the package into our stack, we noticed that a number of auto-generated files have been checked into this repo even though they'll be re-generated by ROS when the package is built.

This PR has two commits: the first simply removes the auto-generated message files and the second adds the directories to ``.gitignore`` so that they do not inadvertently get added again.

I'm not familiar with ``rosbuild`` and so if these files are in fact required to be present, do feel free to close with extreme prejudice :smile:.