Modified RiftFX Classes

Modifed the RiftFX classes so that their particles have noClip = true.
This avoids rifts spamming the collision events of other blocks,
including dimensional doors, and it should improve the performance of DD
a little.
Improved Dim Door Collision Detection

Improved our code for checking whether an entity in contact with a door
should be teleported. Now the check works better, works for Minecarts,
and is more readable. It also ignores particle effect entities.
Minor Change

Removed unused import in TransTrapdoor
Partially Improved Unsafe Exits

Partially completed the code for unsafe exits (used for trapdoors) so
that they drop players into air pockets. It's not complete yet, but I
want to merge in other changes before continuing.