Show number of comments in instance / proposal list

[nidico]

It'd be useful to show the number of comments

• [ ] in the instance list
• [ ] in the proposal list.

The numbers should be cached though to avoid yet more database queries.

[nidico]

We need to clarify whether we show the number of top-level "discussions" or the total number of "comments".

[xi]

I tend slightly towards "comments". But what about "xx arguments/comments in yy discussions"?

[nidico]

But what about "xx arguments/comments in yy discussions"?

Yeah, for the discussion wording case this makes sense. For the comment wording, we should stick with one number.