[XenFocus] Novus 2.3.4

Upgraded for Xenforo 2.3

Upgraded for Xenforo 2.2.13.
Fixed an error when trying to disable the Mega Footer in the admin panel.

xenforo 2.2.9 support

A minor change to the PAGE_CONTAINER template file, introduced in the 2.2.8 Xenforo update, was applied.