Remove redundant import of POSIX strftime
Reduce repetition in test scripts by providing some standard testing functions at toplevel
Also check the 'last_active_ago' presence field
Have the eval()'ed code yield 1 so the functions it calls don't have to
Allow a new kind of script step called 'prepare', which just does things in preparation of other tests
Prepare more local users for other tests to use
Some initial testing on presence list
Put the test assertions in their own package so that 'croak' has a better chance of hitting the right caller package file/line number
Store a helper closure in the test env. to return events occurring after some action is taken