Implemented LongSet and LongTagSet, based on IntSet and TagSet.
Removed some CompiledName attributes -- in this case, it makes more sense just to use the actual type name.
Use checked conversion so if overflow occurs, it won't be silent.
Implemented LongMap and LongTagMap based on IntMap and TagMap.
Implemented LongBimap and LongTagBimap based on IntBimap and TagBimap.