The param() method has been extended to allow multiple parameters to be set at one time, via a hash (or hashref).
Fixed bug in run() method where a null-string run-mode would be considered valid. A zero-length run-mode will now result in the start_mode() being called. (Thanks to Mark Stosberg for the two preceding ideas!)
The run_mode() method now may be called a subsequent time to amend the list of run-modes.