Fixing #101 (Licenses)

- We don't need the top-level LICENSE file and it's empty anyways.
- Waiting for your stance on cudaHog in gitter.
- Everything else is licensed in `package.xml` already; I don't think every package needs an additional `LICENSE` file, or is that a ROS policy?

(I sneaked the license into yesterday's `strands_head_orientation` commits :-))