pfSense

Update include() to include_once()

For safety, use include_once() when including various "side" files.
There are a couple of instances of include("guiconfig,inc") that I
changes to use require_once() to be consistent with everywhere else.
The remaining cases of include() are just (hundreds of) head.inc and...

Remove a-f from IPv4 address pattern

It seems to me that a through f should not be part of the pattern for the "V4" case.
(cherry picked from commit 1f49dd8a3a49b724ded5840c1db6c168ed466aae)

Always use require_once

The usage of require() and require_once() throughout the system is
inconsistent, and "bugs" come up now and then when the order of
"requires" is a bit different and some require() happens after the
include file is already included/required....

Use the translated destination for kill_states if one exists. Ticket #6531

Correct/clarify column header. Ticket #6530

Fix style

pfSense_get_pf_states always returns source as src and dest as dst, this flipping based on direction is wrong. Ticket #6530

Fix style

Comment typo

(cherry picked from commit b069f77e0a5e355e811dd7bd4a4d17a802a3f682)

Revert "adding privileges and separating DNS Resolver overrides from general settings"

This reverts commit fc76a1e390c8ce9579df31457c74d1d0e572b78d.