mod_backup: add phone_mobile to property list

(cherry picked from commit 24dd1a56455acfa115d709d5219d84619eee7494)
core: use universal-time for the erlydtl 'now' tag.

(cherry picked from commit b04ac2b64943251517b197804407691bf0c11bcd)
mod_base_site: list category pages by descending publication date.

(cherry picked from commit c6154622cc4938fc440934d258709d28032f98f2)