* Make the NS file an optional argument to swapexp modify; when not
  given the prerun phase is skipped. Instead, go directly to tbswap
  (run assign, etc).

* Add NSESWAP event so that Shashi can fire off the above modify using
  tevc from an experimental node.

	tevc -e pid/eid now ns nseswap

* Change event scheduler to react to above event, and fire off:

	nseswap pid eid

  as the user. The script should do its thing, and *exec* swapexp with
  the proper args as quickly as possible (so that the event scheduler
  is not hung up for too long. The script is invoked as the user,
  since the event scheduler is running as the user.