Volume on which to store setup executable and cygwin-packages/
Volume on which to install cygwin/ if install-dir param not specified

Signed-off-by: Glenn Strauss <gstrauss@gluelogic.com>

It's measurably faster, so it makes no sense not to use it by default.

Also, disable fail-fast in all test matricies.

Also, don't use a naked catch, so we don't trap sytnax or usage errors
etc., only network failures.

Check that an Authenticode signature on setup is present, valid and made
by the expected key.

Give the action some outputs, so the scallywag build action doesn't have
to guess/hardcode those internal values.

(Note that locating output values relies on the id assigned to a step, a
point which the official documentation could stand to be clearer on)