Progress on Implementing Dungeon Packs

Started implementing our support for dungeon packs. The code is not
usable yet and the mod is not functional at this stage. A few additional
changes should make it testable. A significant obstacle to implementing
dungeon packs easily is that DungeonGenerator doesn't have some
necessary information and shouldn't be modified. Even if it is modified,
old serialized instances wouldn't have the new fields initialized. I'm
having to create workarounds until we implement the new save format.

DungeonPack handles all of the logic of selecting a dungeon and
verifying whether its type is valid. It relies on DungeonChainRule and
OptimizedRule to check which dungeons should be generated next given a
list of the dungeons in a chain. DungeonType maps types in packs to ID
numbers and provides a reference to the pack that owns the type.
DungeonPackConfig will carry config information to be passed to the
DungeonPack constructor.
Progress on Implementing Dungeon Packs

Completed enough of the implementation and integration to compile DD.
Some portions of the code are only for testing and will be removed
later. The configuration for default dungeons is hardcoded - we can
parse config files once we're certain that dungeon chains work. At the
moment, dungeons generate but it doesn't seem like the rules we set are
being followed properly.

Renamed OptimizedRule to DungeonChainRule, and renamed the old
DungeonChainRule to DungeonChainRuleDefinition, to match the role of
each class better. Added some hax to DungeonGenerator to get packs
integrated - the implementation will be much cleaner once the new save
format is done.
Adding DungeonChainRuleDefinition

For some odd reason, git didn't commit DungeonChainRuleDefinition in my
last commit. Adding it again now.
Basic Configurable Dungeon Chains

Completed a basic version of configurable dungeon chains. Almost all of
the final funcionality is present. However, the configuration is
hardcoded at the moment, not read from a file. This was done for testing
purposes. I'll add reading from config files soon.

Dungeon packs are partially implemented. Built-in and custom dungeons
are currently thrown into the default pack, Ruins. The next step is to
generalize the dungeon registration code in DungeonHelper so that we can
detect dungeon packs, read their config files, and register dungeons
with their corresponding pack. dd-export will need to support packs as
well. dd-rift will have issues dealing with duplicate dungeon names
across packs, but this isn't a major concern and can be dealt with in
the long term.
Merge remote-tracking branch 'upstream/master' into DungeonPacks
Merge remote-tracking branch 'upstream/master' into DungeonPacks
Added Nether Gateway Chance Correction

Modified RiftGenerator to correct for the rarity of Rift Gateways in the
Nether. Our config settings allow us to set the probability that we will
attempt to generate a gateway in a given chunk. However, that doesn't
guarantee that a gateway will generate.

I collected a lot of data and determined that generation succeeds in the
Nether only about 15% of the time. That's compared to 30% in the
Overworld when counting oceans (which always fail) and about 75%
(sometimes higher) when traveling mainly on land.

RiftGenerator now corrects for this by multiplying the chance of
attempting to generate gateways in the Nether by 4. Gateways in the
Nether are still relatively rare and hard to find, but you'll
occasionally come across them now. Also reorganized the code a little
for clarify.
Decreased Default Gateway Generation Chance

Decreased the default chance of a gateway generating. This won't affect
users unless they clear their config files. The decision is based on
user feedback and recent experiments on how common gateways could be.
Dungeon Selection Fix and Chain Config Change

Changed how Random is initialized in SchematicLoader to prevent issues
with dim doors in the same chunks leading to the same dungeon. The
selection seems much more varied now. Also changed the hardcoded config
for the default dungeon chains to the one we'll be using later (from a
file). For testing purposes.
Merge pull request #67 from SenseiKiwi/DungeonPacks

Partial Dungeon Pack and Configurable Dungeon Chain Implementation