[TASK] Update copyright year to 2013

Resolves: #46085
Releases: 6.1, 6.0, 4.7, 4.6, 4.5
Change-Id: Idaa18253a29fef44aa4101adea83b53e0b61e9d3
Reviewed-on: https://review.typo3.org/18790
Reviewed-by: Ernesto Baschny
Tested-by: Ernesto Baschny