R1:741477785640

Select all available bodies when rendering a feed story

Summary:
Fixes T4060. The logic here is:

- When you take several actions at once, we show a single feed story for all of them.
- We choose the "most interesting" title for the feed story. For example, "close task" is more interesting than "add CC".

Currently, the issue with this is:

- "Add comment" is the //least interesting// title. I think this is correct: all other actions are more interesting than the fact that you added a comment.