Small but important tweaks to fix the operation of the nut initscripts
and hotplug scripts.  All hail shellcheck and proofreading and
dogfooding.

Signed-off-by: Daniel F. Dickinson <cshored@thecshore.com>

Add option to send email notification via sendmail
(or replacement).

Signed-off-by: Daniel Dickinson <lede@cshore.thecshore.com>