Scrapped the get_surroundings function and wrote it differently because,
frankly, it was a mess.  Now it relies on the buffer instead of trying
to pull directly from chunks.  Much cleaner, because the buffer will always
be there.  And, if part of the surroundings go outside of the buffer, it
gets filled with empty tiles.  I explored ~30 dungeons without a segfault
(still doesn't mean it's not there). I'll valgrind it to check things out.

There are still several issues that I want to put on my TODO list:
-In very very very rare cases, spawners can spawn on top of stair cases
-Same thing for down stairs spawning on top of up stairs
-A seg fault will happen if a spawner tries to spawn in a room less than 2
 spaces wide
-Stairs still occasionally spawn in walls.  I can fix this by applying the same
 algorithm as I did with spawners.