I18n: comments support

[trustmaster]

Add locale to comments, filter comments by locale

[Dayver]

Yes, it does need it

[macik]

Should be any ability to show number of comments in other locales and fast switch to that locale. Some times user can search info in othel lang comments.

For example: I'm by default see russian comments but had links like En (5), De (1), Tr (2) for switch to certain language comments.