PPPoE wasn't removed, which led to some refactoring to find
out why.  The outcome is the same, but works a little bit
different now.  While there, make it possible to omit the
config write in case we are going to call write_config()
shortly after anyway.

This will also be necessary for the legacy VPN plugins.

PR: https://forum.opnsense.org/index.php?topic=3480.0

(firewall, scrub) add direction and source port. closes https://github.com/opnsense/core/issues/1087

Incorrect units capitalization in proxy form

(packet capture) stream/flush output to browser, closes https://github.com/opnsense/core/issues/1116

The other code does more or less the same, but it seems that
a lot needs to be cleaned up still...

PR: https://forum.opnsense.org/index.php?topic=3311.0

PR: https://forum.opnsense.org/index.php?topic=3311.0

Style cleanup (ran make stylefix)

(firewall, alias) move field split to proper location, for https://github.com/opnsense/core/issues/1109