Reworked Basics and Monster Chasing

I had to work a little more than I planned to get the AI chasing working. It turned out I had been hacking the game together a little to hastily (never happened before right?) so some things had to be switched around to make the planned solution work.

I have also thrown in some nifty rotation of sprites that are attached to the tower rotation as well as some graphics for the first monster. I also have a lot of ideas for how to tie it all together design wise now. : )