Fixed bug in RigidBodyTorsionalSpring where spring torque was only applied to the child body (and not the parent).
Merge branch 'drake-origin/master'
Fixes infeasibility when robot starts with toes pointing together
Merge pull request #284 from rdeits/fix-footstep-infeas

Fixes infeasibility when robot starts with toes pointing together
Update RigidBodyTorsionalSpring.m

Not applying force to the parent if it is the world (body 0)
Fix variability in footstep plans based on world pose of the bot

The problem was that as the robot and the goal were moved farther from the origin, a larger constant term was added to the objective (since the objective involves quadratic terms in the goal pose). This would ordinarily not be a problem, but the MIP solver terminates when the optimality gap is less than a certain /fraction/ of the best objective, so as the objective got larger (by a constant factor), the solutions became less optimal. Correctly accounting for this constant (by setting objcon in gurobi) fixes the problem.
Merge pull request #270 from mposa/master

RigidBodyTorsionalSpring bug fix
Merge pull request #285 from rdeits/fix-world-pose-dependence

Fix variability in footstep plans based on world pose of the bot