Minor update to @tickets display

[Timegrinder]

@tickets should now have two slight differences to make it slightly more useful to read:

- The 'Last Update' column will now appropriately provide a timestamp update for comments (previously it had timestamps only when there was a status change)
- 'Last Update' column will now be faded yellow (instead of bright) if there hasn't been an update since:
- You submitted it OR
- You last commented
It will highlight on any changes to the ticket status or new comments from someone that isn't the person getting the ticket list.

EDIT: To clarify, there's no 'read' status on tickets, so even if you've looked at one it will remain highlighted. I understand that makes the change slightly less helpful.

If there's any issues with these not working properly (or for some reason it's NOT doing what I've just said above) please let me know.

For those who have submitted a lot of tickets in the past, you might find many of them have a faded out update time, there's a bit of a back log and we usually triage them for work prioritisation, so smaller (or very old) tickets may seem like we've missed them entirely. We will catch back up to them eventually.

We appreciate your patience.