Re #6371. Minor changes - better memory management in test.
Re #6371. Tests for getFirst/LastPulseTime.
Re #6371. Tidy up of getFirst/LastPulseTime.

The (!log) tests were redundant - the previous lines will throw
if the property isn't there.
Re #6371. Add busy cursors when running algorithms.

My experience so far is that running the algorithms is fairly fast.
This leads me to think that I may not need to run things asynchronously.