First pass at updating RelativeGazeDirConstraint
Add mex for RelativeGazeDirConstraint.
fixed typo in dircol
Merge pull request #106 from avalenzu/RelativeGazeDirConstraint

Relative gaze direction constraint
fix for failing unit test "util/obstacles/test/testVerticalAndHorizontalObstacles" from Ani
Implement the MATLAB version of FootStepConstraint, will work on C++ implementation
Rename 'FootStepConstraint' to 'FootStepRegionConstraint'
Move the commits from drc sandbox to drake. Almost finished the P step of the bilinear alternation
P step is numerically correct. Need to add some kinematic constraint on the distance between CoM and the contact points, so that the contact position makes sense
add a function addKinematicPolygon in the P step to encode the relative position between contact bodies. Will need to work on RelativeFootPositionPolygon to specify such position constraint
RelativeFOotPositionPolygon is implemented to encode the polygonal constraint on the foot location w.r.t the other foot
P step supports a polygonal region constraint on the xy position between contact bodies
Start to work on the 'F-step' of the bilinear alternation. But I will take a step backward and add the time as decision variables in the formulation first
P-step uses less internal storage for the FootStepRegionContactConstraint
P-step now accepts time scaling as input of the optimization
P-step can specify the bounds on the CoM velocity
P-step can run optimization now. Need to check the solution. Will also add constraint on the time interval between consecutive knot points; such constraint are second order cone constraint with additional variables
Add the upper bound for dt in F-step. Also sdot is bounded from below. So now time scaling funtion is bounded
Start bilinear alternation. Something gets wrong that the P step immediately after F step is infeasible.
Find the bug why P step is not feasible. But in the P step there should be a bug in computing the torque