Fixed graphics between HC/Sewers and cross dungeons.
Added base work for spiral staircases in HC/Eastern. (More data needed for other dungeons.)
Added new region to deal with push blocks in Sewers Secret Room
Refactored asm to be in multiple files.
Bug with doors with offset 2 going to doors with offset 2 was fixed in asm.
Refactor asm code to use Y as 2nd index, which cleaned up code.
Also learned the phb:phk:plb ... plb trick (cleaner than what I was doing)
ASAR asm patch included with test tables.
Eastern and Hyrule Castle regions created from a while ago.
Currently broken because boss prizes are unreachable.
