PR: https://forum.opnsense.org/index.php?topic=5466.0

(cherry picked from commit 20ec899a)
(cherry picked from commit 865b2731)

(cherry picked from commit 77401d6a)

(cherry picked from commit d2ab500a)

(cherry picked from commit 218b37df)

PR: https://github.com/opnsense/core/issues/1714
(cherry picked from commit 738f9983)

(cherry picked from commit cbc2292f)

(cherry picked from commit d4b0b2af)

(cherry picked from commit ae54d392)

error: setsockopt(..., SO_RCVBUF, ...) failed: No buffer space available
(cherry picked from commit 9d392294)

(cherry picked from commit cd3a9dff)

PR: https://github.com/opnsense/core/issues/1662

(cherry picked from commit 9bba2092)
(cherry picked from commit c14db1a3)
(cherry picked from commit 24c62ed5)
(cherry picked from commit b6e4e56e)
(cherry picked from commit 6401d20e)
(cherry picked from commit de5ff59f)
(cherry picked from commit 17a9a263)
(cherry picked from commit 3b3ebbbe)
(cherry picked from commit f15eb3b2)
(cherry picked from commit 932a086e)
(cherry picked from commit 9bb3dd61)
(cherry picked from commit 89a81f3e)
(cherry picked from commit a206e8f6)

(cherry picked from commit d5c6ce35)
(cherry picked from commit efd25658)

(cherry picked from commit 73dbbcd7)
(cherry picked from commit c7786bde)

(cherry picked from commit 32e545ef)
(cherry picked from commit 0f73d88f)

(cherry picked from commit ac75ef6f)

(cherry picked from commit c5f11e99)

(cherry picked from commit 92d1886c)

fix logic error in the behaviour of fixup_default_gateway()

(cherry picked from commit 532ee5bc)

This reverts commit c4628a0b.
It looks like pkg can't handle php70 to php71 at all.

(cherry picked from commit da68e436)

(cherry picked from commit c4628a0b)

(cherry picked from commit 3e527d8f)

(cherry picked from commit d0d52b08)

(cherry picked from commit 6d8812c8)

(cherry picked from commit 203ba240)

(cherry picked from commit f039e921)
(cherry picked from commit 85279119)

firewall_rules, keep category selection when changing tabs. closes https://github.com/opnsense/core/issues/1592

(cherry picked from commit e660269e)
(cherry picked from commit d5ceec2a)

(cherry picked from commit b16ea822)

(cherry picked from commit 965b6eba)

(cherry picked from commit 8a0e3bc7)
(cherry picked from commit 5f1f9cae)

(cherry picked from commit fe571ac4)
(cherry picked from commit c998907e)

(cherry picked from commit 9398670a)

(cherry picked from commit a7825a60)