Suggested by: @andreas-p
Inspired by:  pfSense

(cherry picked from commit 79a2008b)

(cherry picked from commit b95a654c)

(config) switch default for offloading features, closes https://github.com/opnsense/core/issues/1092

(cherry picked from commit 4e662fe4)

(cherry picked from commit 4be83432)

(cherry picked from commit e7cb49b8)

(cherry picked from commit 7fe0f4c1)

(cherry picked from commit 796d3778)

(cherry picked from commit 7a610b2e)

The custom scrub rules on the normalization settings page effectively
cannot be reached since the standard interface scrub rules are listed
first.

This patch swaps that order around so that custom scrub rules get
evaluated first.

(cherry picked from commit 23ea5bcf)

(cherry picked from commit 0a71d2ea)

"index.php*" match in dashboard privileges overlays a bit
with "index.php?logout" so that we'll have to hardcode an
exception for now.  Other approaches to be taken here mid-
term are 'visibility="always"' in Menu.xml or restructure
the logout link under /ui/logout or /logout.php.

PR: https://forum.opnsense.org/index.php?topic=3431.0
(cherry picked from commit 6a089c21)

(cherry picked from commit b881dfef)
(cherry picked from commit 241b29f7)

(cherry picked from commit 155fca31)

(config/interfaces) some older configurations use <enabled/> in stead of our current standard <enabled>1</enabled>. to avoid new issues, its better to convert when only set.

(cherry picked from commit c17a834f)

Firefox and Safari are unaffected.  No harm done in deleting a
pointer to a non-existing source map.  Oh my.

(cherry picked from commit 6a1ddbf7)

(cherry picked from commit e061374a)

(cherry picked from commit ba75faeb)

(cherry picked from commit f034bccf)

Inspired by: @adschellevis

(cherry picked from commit b72bfe22)

maybe, one day, we should refactor some of the JS code... but for now this will do the trick

(cherry picked from commit 6c8c91a1)

(reporting/settings) option to flush all local netflow data. closes https://github.com/opnsense/core/issues/983

(cherry picked from commit 0c429413)

(cherry picked from commit 57f35d74)

(cherry picked from commit 2641694a)

(cherry picked from commit f9e71141)

(rrd) add configd "systemhealth flush" command, add flush single report. closes https://github.com/opnsense/core/issues/984

(cherry picked from commit b7657a6f)
(cherry picked from commit 6bbfe4e0)

Bravely assisted by: @ShaRose

(cherry picked from commit 768d5e81)

(cherry picked from commit 1e5c55bf)

(cherry picked from commit 51b04e9b)

(interface groups) trigger missing to notify changed interface administration, closes https://github.com/opnsense/core/issues/1064

Language correction: more generic expression