Working minimap & performance improvements

minimap now "follows" you

Performance improvements!
- for both main map and minimap:
if you got too far from (0,0), the loop would have to loop all the way
through the array to get to your current coordinates, so you'd get lower
FPS the further away you were from 0,0. However, I made the loop start
at p.getX()-startx (y similar) so that you don't loop through the entire
array! yay! fps! yay!

I would be really flustered if these commit messages were made public
(to people who knew me in person)