map.contents always has 1200 tiles in it, there's no reason it should be
a vector.
This is a big commit because it requires changing all the level classes
to return a pointer to an array instead of returning a vector. Which
took a while for me to figure out, but eventually I did it. I tested to
make sure and there's no problems.
Instead, they're all stored in a constant int array.
I made sure The Gravitron still has 30 rows just like Outer Space,
though I don't think it matters.
