Pause button, fix bot and stick finding logic, logging, UI fixes, test code and refactoring

- Added system pausing functionality
- Fixed red pixels finding logic: had to swap hue and brighness
channels (dont know why still)
- Fixed bot center finding logic to look for circle with largest area
instead of circumference
- Added log4j logging
- Moved path planning out of Robot class. The Robot should take a
planned path as input instead of calculating it by itself.
- Added path rendering UI code
- Added test classes
- Refactoring