A cleaned up and ready-to-copy cart elevator as seen on plr_hightower. Also includes a mid-track elevator.

Notes:

• The prefab is set up to allow a team_train_watcher to handle rollfoward and rollback zones using only flags, so no manual outputs are needed. As a result, there are two team_train_watchers for each cart.
• Elevator path_track entities have the Orientation Type set to "Face this path_track's angles". If rotating the elevator, make sure to change these path_tracks' angles as well.
• The elevator platform consists of a func_brush and a func_tracktrain. Both of these must look identical, and their origins must be aligned with the center of the "clamp_track_*_1" path_track entity.
• Bugs from plr_hightower's elevator still persist, such as the cart sinking into the platform when the trigger is touched while it falls quickly.
• Use the logic entities originating from this prefab, including the carts, or the elevator may not work properly.