#4: Refactor AsyncHolonomicChassisController

[Ryan4253]

Made the following changes to AsyncHolonomicChassisController and its builder

• Removed race condition associated with getPose() by wrapping a mutex around it
• Simplified calculation, removed (lots of) redundant variables
• Added Pose constructors for OdomState, TrajectoryState and TimedTrajectoryState to directly convert between different coordinate systems
• Reduced the number of PID controllers to 2 (dist + turn instead of x + y + turn) to simplify tuning
• Expanded settling conditions. The users can now specify maximum error, derivative and wait time for both dist and turn controllers
• Made the builder constructor take the chassis pointer since we require it anyways
• Added a check in build() to make sure that the user actually supplied an OdomChassisController built with x drives
• Fixed a small bug related to sample time and how okapi deals with derivatives
• Commented Code

Note: this is a fix to Issue #4

[Ryan4253]

Alright @Yessir120 I fixed the issues and cleaned up the commits, should be ready for a merge. Remember to close the issue after merging. Note that you might want to test the code

[jazonshou]

@Ryan4253 Looks good. One more thing, can you change the PR so that it merges with the development branch? I want to try this system where untested code goes to one branch, and after it gets tested, it moves to the master branch.

[Ryan4253]

done