Translation Message Updates for CN

centralnotice-confirm-delete is deprecated and removed from translation
-- The only source file that uses it TemplatePager is itself being
   deprecated and is no longer used except as a base class. Child clases
   do not use this message.

centralnotice-start-date had Date vs. Date & Time translation issues so
it is now more clear hopefully.

Change-Id: I4ec594bf4a1b06aee3b028473f87566c4ab44073