helpgroups-789884: Display parameters in groups

Parameters can be grouped, but the help command didn't display the
groups when it listed the parameters. Now it does.

Signed-off-by: Joe Walker <jwalker@mozilla.com>
isodate-892901: Fix date parsing in non UTC timezones

See inline comments for details.

Signed-off-by: Joe Walker <jwalker@mozilla.com>
filterparent-773188: Filter out parent commands

This involves some refactoring of selection.js because we're copying
_findPredictions() from selection.js to command.js (since there are
enough differences now that unifying them is making them more complex)
So we can simplify _findPredictions() in selection.js.

Signed-off-by: Joe Walker <jwalker@mozilla.com>
refactor-864370: Improve test summary output

Signed-off-by: Joe Walker <jwalker@mozilla.com>