(cherry picked from commit f4ac7431)

(cherry picked from commit d7a42b2c)

See: Refused to set unsafe header "Content-length"
(cherry picked from commit e0c24b5e)

(cherry picked from commit 30b63eeb)

(cherry picked from commit 688f6574)

We don't have this on master, so this needed a manual adapt.
I'm overwriting the new Captive Portal Menu.xml out of convenience,
this way it's impossible to have both entries in the menu when
using core mount.

(cherry picked from commit a858b479)

(cherry picked from commit c2933dc2)

(cherry picked from commit ffbbd11e)

(cherry picked from commit 9a22c04f)

(cherry picked from commit 7968b548)

(cherry picked from commit 97b56090)

(cherry picked from commit f9129538)

(cherry picked from commit 5a317b09)

This roughly equals to:

o Reworks of routing, gateways and settings pages
o Menu restructuring and tab removal
o Layout and padding improvements
o Log file viewer improvements

(cherry picked from commit 7f7fde41)

(cherry picked from commit ef486094)

(cherry picked from commit 192b6eb6)

(cherry picked from commit 4370f811)

(cherry picked from commit 7f1c91f7)

(cherry picked from commit 6dcbac7a)

(cherry picked from commit a4cd1e46)
(cherry picked from commit 4a618919)

(cherry picked from commit 14d3ba6e)

(cherry picked from commit 523a4711)

(legacy) crashreport strpos() expects parameter 1 to be string, array given in /usr/local/www/firewall_rules_edit.php on line 747

(cherry picked from commit 84ba6a49)

Spotted by: @fabianfrz

(cherry picked from commit 8ac115c9)

(cherry picked from commit c6ff30e4)

o Page did not work with translations.
o Selected serial device wasn't shown.
o Very old gpsport migration code zapped.
o set_gps_default() must trigger on load.

(cherry picked from commit bb55f6c0)

(cherry picked from commit f1c28948)

(cherry picked from commit 48acede9)

(cherry picked from commit 1d43bced)

(cherry picked from commit 09f9ace8)

(cherry picked from commit ddc987e2)

(cherry picked from commit 2daf0e20)

(cherry picked from commit 7413cd78)

(cherry picked from commit 3ba6fecf)

(cherry picked from commit 1c2ea230)

(cherry picked from commit e2b1f644)

everywhere, anytime, just for fun...  first of many :(

(cherry picked from commit 3df63a5d)