Adds Professor Kane character WIP

Thanks to [Condoreo](reddit.com/u/Condoreo), we have a new character. What do you guys think? I think his head changes sizes when he holds a weapon & his hurt animation is weird. Do you have any comments or suggestions for the sprite sheet? I think it's better to test it out when playing the game than looking at a single image.

I've also got rid of Kevin as a separate character and added him as a Chang costume.

Still to do:
* Check through sprite sheet for errors
* Make an overworld sprite
* Do hand positions (currently using Jeff's)