(cherry picked from commit dd0d8ed8)

According to: https://redmine.pfsense.org/issues/3669

(cherry picked from commit 575f804a)
(cherry picked from commit ad5ad50e)

(cherry picked from commit 15f48662)
(cherry picked from commit f8547f27)
(cherry picked from commit e438bfc9)
(cherry picked from commit 23c2cce6)

(cherry picked from commit c2e0d912)

PR: https://forum.opnsense.org/index.php?topic=5140.0
(cherry picked from commit 9c88e641)

(cherry picked from commit 1146fb24)

An API exception occured
Error at /usr/local/etc/inc/plugins.inc.d/dyndns/phpDynDNS.inc:92 - Methods with the same name as their class will not be constructors in a future version of PHP; updatedns has a deprecated constructor (errno=8192)
(cherry picked from commit 7560c617)

PR: https://forum.opnsense.org/index.php?topic=5120.0
(cherry picked from commit 45707768)

PR: https://forum.opnsense.org/index.php?topic=5099.0
(cherry picked from commit 9939ff28)

(cherry picked from commit f12c505a)

See: https://github.com/pfsense/pfsense/commit/12df7edc
(cherry picked from commit c8ef950c)

Looks like the reason for this file has gone.  We shall merge
the code into config.inc soon.

(cherry picked from commit cde9b8f8)

(cherry picked from commit 2d2771ac)

filter, alias, don't reload immediately after delete, closes https://github.com/opnsense/core/issues/1601

(cherry picked from commit 89784b84)

(cherry picked from commit 320cc256)

pconfig_to_address, don't save range when $endport is 0, closes https://github.com/opnsense/core/issues/1611

(cherry picked from commit 0280a875)

(cherry picked from commit 575c6440)
(cherry picked from commit 6009ab93)
(cherry picked from commit 834ccbe0)
(cherry picked from commit 5376a0ec)

PR: https://forum.opnsense.org/index.php?topic=5099.0

(cherry picked from commit 1417414b)
(cherry picked from commit ef1dc387)
(cherry picked from commit ecace09a)

(cherry picked from commit f5c25d72)
(cherry picked from commit 2abbf0dc)

(cherry picked from commit 6d443755)
(cherry picked from commit 2d42d843)

If configd doesn't respond the JSON is not available, which we really
need a wrapper for doing this fallback all the time and maybe even
with error reporting inside that returned array.

(cherry picked from commit d79c1acf)

(cherry picked from commit 7a78cc99)

OpenVPN servers using udp6 or tcp6 fail to start, closes https://github.com/opnsense/core/issues/1576

(cherry picked from commit daa58810)
(cherry picked from commit 3abd54ae)

(cherry picked from commit 852657c7)

(cherry picked from commit 025021b8)

dhcp server / static leases, issue with loading settings into form. closes https://github.com/opnsense/core/issues/1568

(cherry picked from commit 8e0583e9)

(cherry picked from commit ae677059)

(cherry picked from commit 1626ab87)

(cherry picked from commit 8ca337c9)

(cherry picked from commit 829e0aa2)
(cherry picked from commit 8c6c1f5e)