Merged r2986 from trunk.
Do not show user profile if no visible project or activity (#4129, #3720).
Typo fixed (#4134).
Merged r2983 from trunk.
Fixed error on repository when there are no comments in a changeset (#4126).
Add etag check on the activity view to avoid rendering when not modified.
Add indexes on various timestamps to speed up the activity view.
IssuesController#destroy accepts POST only (#4107).
HTML escaping (#4106).
Add translations for new permission.