Continued with fax, land-line, mobile: (please cherry-pick)

Continued with fax, land-line, mobile: (please cherry-pick)
- added getter/setter for choosen fax/land-line numbers
- added template includes for fax/land-line numbers (admin_show_contact)
- added created/updated timestamp for fax/land-line/mobile data
- added templates for fax/land-line "selection boxes" (input forms, needs renaming)
- introduced template admin_user_data.tpl (similar to admin_contact_data.tpl)
- fixed "add" EL code for fax/land-line numbers
- renamed some i18n strings as they can be combined into a generic "Administrative links" string
- added missing i18n strings
- added suffix _NUMBER to i18n strings as they are about ("phone") numbers ...

Signed-off-by: Roland Häder <roland@mxchange.org>