Merge pull request #38 from hersh/hydro-devel

New concave meshes.  Visuals are full-res, collisions are decimated.
Manual merge of @ben-ebersole pull request to add gazebo parameters
Reversed MH5 base mesh.  Was on backwards.
Merge pull request #40 from hersh/mh5-base-reversal

Reversed MH5 base mesh.  Was on backwards.  Thanks for the contribution!
Added error-return from streamer to action server.