Made it so rifts destroy blocks in layers rather than destroying random
surrounding blocks, even through indestructible blocks. This resolves
issue #24.
Fixed the bugs that caused doors not to appear right in dungeons. First
there was a bug with filters that caused them not to replace blocks
properly. I made some changes to SchematicFilter and its derived classes
so that the implementations are a little more intuitive. That should
prevent those bugs in any future derived classes. Then doors wouldn't
rotate properly. DD was never designed to rotate dimensional doors. I
added code to BlockRotator for that and shifted some code from
DungeonHelper to BlockRotator. More coherence, less coupling!
It turns out my earlier commits didn't completely fix things because
certain implementation details were missing. I had assumed they were
done. Also, some of the information I had regarding the default
schematic orientation was wrong. This commit remedies most of those
problems with a robust rotation implementation. However, I haven't added
the code for linking Warp Doors yet, and there is a bug with tile
entities getting reversed in East/West oriented rooms. Not sure why
that's happening.