[Translators] Update for Slovak translation of VLC

[Marián Hikaník]

Hello,
I updated the Slovak translation for VLC Media Player. You can download the updated file from http://www.mojepreklady.net/download/po-sk.zip

I tested this translation with the latest trunk version of VLC 1.2.0 and found a problem. Some strings are not accepted and loaded from language file 
for Slovak, but translation should be complete. You can see this problem in main menu of VLC, if you activate Slovak language. Some strings in 
main-menu are still in English (e. g.: Open file..., Open (advanced), or Always fit window and other strings too).

The same problem is visible on more places in user-interface (in Preferences too). Strings are often not translated. Restart of VLC did not solve this 
problem. This problem was here already in the past, but then was solved for a long-time. Now I see it again. Could you please test and solve it?

Thank you for your answer. Best regards,

-- 
Marián Hikaník