added obstacle class
HitBox added to sprites, collision test not yet implemented
Merge pull request #15 from RoboNickBot/obstacles

Obstacles and HitBoxes
simple graphics
Merge pull request #18 from lijiaqigreat/simplegui

simple graphics
made sprite fields a little clearer
Merge pull request #19 from RoboNickBot/spritechange

made sprite fields a little clearer
initial commit of untested Game, Player, and InterfaceWithGame
SimpleTanks have access to owning player's spritelist
GAME AND PLAYER STRUCTURE TESTED AND WORKING
Merge pull request #20 from RoboNickBot/players

Game, Players, and InterfaceWithGame interface
change direction, add collision
Merge pull request #23 from lijiaqigreat/direction

change direction, add collision
Merge branch 'master' of https://github.com/RoboNickBot/ateam-tanks