New character controller released

[Norbo]

Since v0.7.0 won't be ready for a little while, I went ahead and finished up an early version of the new character controller. It's not perfect, but it should be a significant improvement in usability compared to the earlier versions. The source code is released under the same permissive zlib-style license as the demos: http://bepu-games.com/BEPUphysics/demoslicense.txt.