Partially Fixed Exit Doors

Added code so that exit doors will search for a destination and place a
platform for the player on the other side. However, the search function
only searches upward, not downward. I'd like to discuss some details
about this before completing the implementation:
1. How should the search work?
2. What should be the likelihood of a dungeon exit leading to a
different root dimension than the dungeon's actual root?

I've tested the exits and they're working well.
Merge remote-tracking branch 'upstream/DevBranch' into rewrite
Cleaned Up Code

Deleted PlayerRespawnTracker and removed all references to it - we
weren't going to use it anymore anyway. Renamed IDDoorLogic to IDimDoor
- abbreviating the "Dim" as D next to the standard I for Interface is
confusing. Renamed DDoorBase to BaseDimDoor and made it into an abstract
class - that's effectively what it was supposed to be. We should be
declaring methods as abstract rather than using empty ones. I renamed
the class because the convention for naming abstract classes is to start
the name with Base. Cleaned up code in other files.
Minor Changes

Changed EventHookContainer.LivingDeathEvent() to use the player's max
health instead of a fixed health value. No magic numbers! Also cleaned
up the code a little.
Merge pull request #85 from SenseiKiwi/rewrite

Partially Fixed Exit Doors