[css3-animations] Duplicate animation names

It's not really clear what happens if the same identifier appears multiple  
times in the 'animation-name' list.

WebKit seems somewhat buggy, but I think it intends to have only the last  
occurrence apply. Gecko applies both (giving two separate animations if  
they don't fully overlap in time).

-- 
Øyvind Stenhaug
Core Norway, Opera Software ASA