(cherry picked from commit a7e4762b)

(cherry picked from commit 96b0b961)

Long story short: we don't want contrib code inside src/opnsense/contrib
so a few things need to be shuffled.  First pass is moving the current
contrib stuff to the same location instead and migrating the non-code
tzdata file.

(cherry picked from commit b1120c8e)

(cherry picked from commit 3d7d9078)

(cherry picked from commit c5299dba)

(cherry picked from commit 2da105f0)

(cherry picked from commit 33004e87)

(cherry picked from commit f57ac817)

(cherry picked from commit 7717d736)

(cherry picked from commit ebaef43b)

(cherry picked from commit fbe855ab)

(cherry picked from commit e5c48cf6)

(cherry picked from commit bf229dff)

(cherry picked from commit 9a44a854)

o Can't unset the session var anymore resulting in permanent
  login error message display until login was successful.
o Remove some padding and make permanent room for the error
  message so that the container doesn't grow after submit.
o Move the workaround to a permanent position in <button/>.
o Move the copyright right line right underneath the container.

(cherry picked from commit dbe860f0)

(cherry picked from commit 21136d00)

(cherry picked from commit abc621a2)

(cherry picked from commit be965a7f)

(cherry picked from commit 17c2d4e2)

(cherry picked from commit 5997f1df)

(cherry picked from commit 9ae707fe)

(cherry picked from commit 9defc2f4)

(config) automatic recovery when config is broken, closes https://github.com/opnsense/core/issues/701

(cherry picked from commit 6e8f51d4)

(cherry picked from commit 1a891bc4)

(cherry picked from commit 8ab78eff)

note: there's no trigger to perform the sync, so currently differences are only synced in the slipstream of otther events.
The events around synchronisation and reloading services really need some work sometime....

(cherry picked from commit 1a4a3229)

(cherry picked from commit 63af1e7c)

(cherry picked from commit 2751f6f9)

(cherry picked from commit ab17de8c)

(cherry picked from commit debe657e)

(cherry picked from commit 1d7709a3)

(cherry picked from commit 93900e30)

(cherry picked from commit 9bad3cae)

(cherry picked from commit b9bdf249)

(cherry picked from commit 6b82edd1)

(cherry picked from commit f91112ed)

(cherry picked from commit a0fc0985)

(cherry picked from commit 147fc0c7)

(cherry picked from commit 8474d126)

(cherry picked from commit 2b4858fc)