adding quadrotor trees from Gerardo
Add .vtm files for Atlas meshes.
Add .vtp files for Atlas model.

I've kept the same directory structure that we have in the DRC repo. If there's
a cleaner way to organize the 'meshes' directory, I'm all for it.
Merge branch 'master' of https://github.com/RobotLocomotion/drake
Merge branch 'playing_with_mpc' of https://github.com/RussTedrake/drake into quad_forest
adds display routine to nonlinear program
quadrotor obstacle avoidance example works--most of the time. still only checking for collisions at the knot points (so it still clips sometimes), and of course it can get stuck in local minima
Merge branch 'master' of https://github.com/RobotLocomotion/drake into quad_forest
fix documentation
makes the mesh parsing logic a little more robust
addressed code review comments
addressed code review comments
obstacle dircol seems to work just as well (better?) without the initial seed.  makes me suspicious that the output of the original dircol was not being passed correctly a the seed for the second dircol
Merge pull request #229 from RussTedrake/better_mesh_parsing

makes the mesh parsing logic a little more robust
visualize knot points on trajectory display
Merge pull request #227 from RussTedrake/quad_forest

Quad forest
Merge branch 'master' of https://github.com/RobotLocomotion/drake