Updated DDTeleporter

Updated DDTeleporter to have a fixed minimum chance of sending the
player to the Nether when using a dungeon exit. This also allows players
to reach the Nether without ever having been there before using a Nether
portal - that was previously impossible since DD would not "know" that
the Nether existed. Also cleaned up the code a bit and possibly fixed a
bug that would cause players to get teleported into walls.
Merge remote-tracking branch 'upstream/master'
Minor Change

Added a warning on some hacky code for sending dim data.
Merge remote-tracking branch 'upstream/master'
Chunk Bug Fixes

Added chunk.setChunkModified() to other classes that were missing it. We
have several copies of setBlockDirectly() spread around that needed
updating. Also made pockets use FoR instead of glowstone. =P
Merge pull request #131 from SenseiKiwi/master

Updated DDTeleporter