Physics update

[chrismbirmingham]

Updated the physics engine to Havok. At this point I still plan on updating some of the moonbase assets to take advantage of the physics engine upgrade (making them more graspable).

[tcorbly]

Looks like cloning the fork instead of switching from the master branch worked. Here are a few of the things I've noticed so far:

• Objects in the world do not reset when the reset world button is clicked.
• Motor speeds appear to be around half the speed they were previously.
• When the robot stops the back of it flips up a little bit. This may be solved by changing the weight on some of the parts of the robot.
• The wheels tend to slide a bit during turns. This may be solved by changing friction on the wheels
• So far zero issues with the robot sliding over time!
• In JBC sandbox A, there is a second A mat overlaying the A mat that seems to be mirrored after switching between scenes. Not there after a page refresh
• In JBC Sandbox B, the A mat is overlaying the B mat, should just be B after switching between scenes. Not there after a page refresh
• The robot's starting rotation is labeled as -45 degrees. It should be 0 to start but still be in the same position
• Reflectance sensor are not picking up any readings and should be on port 1 instead of port 3
• When the robot is touching another object at the end of its run, both objects go flying as soon as the run finishes
• Hard to tell on my end but positions and things like that for challenges (6c would be the one to look at) don't seem to be the same or able to be reset