Add swappable and priority bits to experiment creation form. Not used,
but simply entered into the DB record for the experiment until we know what to do with them. Add to batchexp script arguments, since all that stuff is done outside the web interface. Add a swapexp perl script to swap an an experiment in/out form the command line. Add web links on the Experiment Information page to do this from the web interface. A bunch of locking changes. Previously expt_terminating in the experiment record prevented multiple calls to terminate an experiment, but now we have a more general locking problem with start,swapin,swapout, and terminate, so change expt_terminating to expt_locked (still a datetime field) and add locking to all of startexp, swapexp, and endexp. Note that batch experiments cannot be swapped yet because of locking issues still to be resolved. Minor cleanup in tbreport to make email message look better.