- Add bugC.js (The Fly)
- Add 'attack' animation to bug.js. This animation purpose means the bug
is currently attacking the player.
- fix the movement problem in bug.js by setting the accel, vel and
maxVel to values according to the angle
- enhance the code clarity in bug.js
- remove comments and logs
- add distanceToMouse() and sidtanceToPoint() to base.js