Ticket: #23248
(cherry picked from commit a745350e)

fix(gui): make sure gateway is not empty, avoiding traceback

Ticket:	#25061
(cherry picked from commit 421f94fb)

Ticket:	#24918
(cherry picked from commit 873d0fa7)

Ticket:	#24918
(cherry picked from commit a7275a46)

Ticket:	#24918
(cherry picked from commit 3a33bca3)

Ticket:	#24534
(cherry picked from commit 2b392de9)

Fix 24864

Ticket:	#24849
(cherry picked from commit 71b79506)

Ticket:	#24849
(cherry picked from commit 2eec79d5)

Ticket: #24864

fix(network) Address post-review concerns: Remove get_interface() as we have the interface already, also parse all INET objects from a given IFACE instead of p
arser the first item only, in this case we can cover all aliases from a given IFACE. Also remove unnecessary cast.

Ticket: #24864
Reviewed by: william-gr

fix(network): If we attempt to add a IPv4 gateway that is not reachable through any interface, it lead us to have a traceback on GUI or even sometimes a task blocked in the middlewared. Now we fail earlier and we let user know via GUI that gateway is unreachable.

Ticket: #24864

gmirror before creating a new one.

Ticket: #24846
(cherry picked from commit 1a152f76)

Ticket: #24834
(cherry picked from commit fb55a19b)

Ticket: #24834
(cherry picked from commit 113b30b1)

Ticket: #24834
(cherry picked from commit 55275930)

Ticket: #24834
(cherry picked from commit 187ce626)

Python currently uses sem_timedwait(3) to wait for pthread Lock
and that function uses CLOCK_REALTIME clock, which means a system
clock change would make it return before the time has actually passed.
The real fix would be to patch python to use pthread_cond_timedwait
with a CLOCK_MONOTINOC clock however this should do for now.

Ticket:	#24761
(cherry picked from commit 64f9df0a)

It is possible the stdout/stderr will block if the script is not handled
properly (Have seen it happening on lockd rc.d), and since we don't use
the output for anything, lets use DEVNULL.

Ticket:	#24312
(cherry picked from commit f252577b)

Ticket:	#24235
(cherry picked from commit 9bd8cbf5)

Ticket:	#24506
(cherry picked from commit e5f87c88)

Ticket:	#24506
(cherry picked from commit 6de6700e)

Ticket:	#23196
(cherry picked from commit db75f382)

Because, whats the point? I believe readonly was created to be set for
builtin templates.

Ticket:	#24548
(cherry picked from commit b960cc7d)

Ticket:	#24563
(cherry picked from commit 12ed513a)

Ticket:	#24570
(cherry picked from commit d34a68c0)