[Translators] Update Khmer Translation for VLC 1.1.8

[Khoem Sokhem]

Hello Xtophe,

This is the updated Khmer translation for VLC. The .po  file can be download 
from the link below.
http://www.4shared.com/file/hZYQuhIT/km_online.html

Could you please help to merge?

Thanks,
Sokhem