Reset Application Files for replay

If your application processes files that need to be reset during a replay, you can write a handler to do that for you each time you run the program:

(dbx) when sync { sh regen ./database; }
(dbx) run < ./database...	# during which database gets clobbered
(dbx) save
...              # implies a RUN, which implies the SYNC event which
(dbx) restore	   # causes regen to run