minor fixes to PPTrajectory.append
sketch_mesh draws on the current figure
pass collisionRaycast through from TSRBM to RBM
added torsional_spring_damper to drakeURDF.xsd
Merge branch 'master' of https://github.com/RobotLocomotion/drake into urdf_fix
updated comments to reflect addition of torsional_spring_damper in drakeURDF.xsd
minor updates to urdf spec
first pass at urdf parser and force element implementation for torsional springs
Merge branch 'master' of https://github.com/cmmccann/drake into torsional_spring
added torsional_spring_test.URDF
Merge branch 'master' of https://github.com/cmmccann/drake
torsional spring parsing works.  but test case fails
updating torsional spring test
fixed torsional spring.  passes unit test.  simulation looks right
checkDependency at beginning to prevent silly crash
Merge pull request #195 from rdeits/rd-raycast-passthrough

pass collisionRaycast through from TSRBM to RBM
Merge pull request #198 from rdeits/rd-move-checkDep

checkDependency at beginning to prevent silly crash
respond to Robin's code review
Merge pull request #196 from cmmccann/torsional_spring

Torsional spring
respond to Robin's code review