Update refcards/*.tex short copyright year to 2011.

Update refcards/*.tex short copyright year to 2011.

* refcards/calccard.tex, refcards/cs-dired-ref.tex:
* refcards/cs-refcard.tex, refcards/cs-survival.tex:
* refcards/de-refcard.tex, refcards/dired-ref.tex:
* refcards/fr-dired-ref.tex, refcards/fr-refcard.tex:
* refcards/fr-survival.tex, refcards/orgcard.tex:
* refcards/pl-refcard.tex, refcards/pt-br-refcard.tex:
* refcards/refcard.tex, refcards/ru-refcard.tex:
* refcards/sk-dired-ref.tex, refcards/sk-refcard.tex:
* refcards/sk-survival.tex, refcards/survival.tex:
* refcards/vipcard.tex, refcards/viperCard.tex:
Update short copyright year to 2011.