A_02

Balance Changes:
- You can no longer doublejump after a superjump (wall grabs will still
reset the doublejump)
* Increased max fall speed, to further reduce "floating" feeling
* Increased max wall slide speed slightly
+ If you crouch while wall sliding, your fall speed will increase (reset
when not crouching)

Bug Fixes:
+ Image is now scalable on the player
* Changed loadImage to take a width and height, for image scaling
+The player now automatically grabs keyboard focus while the game is
unpaused, to keep from being uncontrollable

Small tweaks:
+ Added res folder, to hold both img and sound
+ Added RESIZE_CROUCH variable to Player, to control whether to resize
the image while crouching
+ Moved acceleration code to its own method, getAcceleration(), so it's
easier to find