Fixed Metadata Rotation for Stairs

Changed BlockRotator so that missing stair types are recognized for
applying rotations. The general code for all stairs was there but the
block IDs for wooden and brick stairs weren't recognized. Also removed a
duplicate reference to nether brick stairs.
Added Support for More Metadata Rotations

Added support for rotating the metadata of powered tracks and detector
tracks. Also made a minor change to DungeonSchematic to protect its
internal state.
Added Support for Activator Track

Added support for rotating the metadata of activator tracks.