Problems:
1. Without a message, users don't find 'last'
2. Showing a message for every error clutters output.
This tries to address these issues by:
1. Only showing the message when other feedback has not been provided and
'last' would not usually be helpful. This will require ongoing tweaking.
For now, all commands except 'compile' display the message. 'update' could
omit the message as well, but perhaps knowing about 'last' might be
useful there.
2. Including the exact command to show the output:
last test:compile
and not just
last <task>
3. Highlighting the command in blue for visibility as an experiment.
Review by @ijuma and @retronym, please.
Mark Harrah