Continued with cell phone: (please cherry-pick)

Continued with cell phone: (please cherry-pick)
- completed listing of all cellphone number data
- renamed method to allCellphoneNumbers() to have it nicer named
- renamed admin_contact_cellphone_list.xhtml to admin_cellphone_list.xhtml as this is generic
- removed _contact from cellphone navigation rules
- introduced new general phone controller (not administrative) with application-scope to have all cellphone, land-line and fax numbers being cached
- moved proper attributes (fields) and methods to that new controller
- added missing navigation case for  admin_cellphone_list.xhtml
- added missing i18n strings

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