Merge pull request #7 from blandry/master

Flapping traj opt
Still in the middle of a lot of things, namely texturing the models to work with the new visualizer, but I'm just passing along the current status of things
textures work in new visualizer, but the model will not load in the old one, unfortunately. Still need to adjust all the parameters for the various runPassive, runFlapping, etc scripts to account for increase in number of joints
made compatible with old viewer
fixed force elements in URDF
dircol flapping for model 12