(auth, vouchers) Vouchers, support for custom length / easier usernames and passwords. closes https://github.com/opnsense/core/issues/886

Checking out a ports tree seems to be a bit over the top.

(auth / vouchers) add option for less secure passwords, password and username length. for https://github.com/opnsense/core/issues/886

add link to proxy page and extend the nat template

enable jinja2 loopcontrols extension

PR: https://forum.opnsense.org/index.php?topic=2273.0

Not explained why added in 2012 and never touched since.  Also only
works on one device.