[BUGFIX] Sprite icon not shown

If first hit after clearing cache was not in BE context
the page contains-news icon is not part of the sprite css.

This patch makes sure that the page contains-news icon
is registered in every context.

Change-Id: Id6b9e8c354569f63b50c6ee5965eff2646e3834e
See: http://forge.typo3.org/issues/58758
Reviewed-on: https://review.typo3.org/30093
Reviewed-by: Georg Ringer
Tested-by: Georg Ringer