Order status updates alphabetically by their summary.
Order status updates alphabetically by their summary.

Status update items in the initial status updates entry or change description
entries were getting ordered by whatever the database was returning, which was
likely to be the creation order. This could be seemingly random based on the
order that Review Bot (or similar tools) would run and latency of communicating
with the workers.

This (very small) change orders the status updates query by their summary. This
ordering then gets preserved as we sort them all out into their respective
entries.

Testing done:
- Ran unit tests.
- Created a couple status updates with timestamps that would display them in
  non-alphabetical order. With this change applied, they now show up
  predictably.

Reviewed at https://reviews.reviewboard.org/r/9278/

reviewboard/reviewboard,reviewboard/reviewboard,chipx86/reviewboard,chipx86/reviewboard,chipx86/reviewboard,chipx86/reviewboard,reviewboard/reviewboard,reviewboard/reviewboard