Remove dead code from `diffReviewableview`

Remove some unused variables and computations from `DiffReviewableView`'s
`_updateCollapseButtonPos` method.

Reviewed at https://reviews.reviewboard.org/r/6455/
Merge branch 'release-2.0.x'
Fix the redirect in the review reply draft resource.

The redirect was passing the wrong variable to get_href(), causing an
HTTP 500 on access. This fixes the variable.
Fix a regression in saving comments.

The new delayed notifications for "change" events from MarkdownEditor
could result in text being chopped off if typing and saving within half
a second. We now make sure to always set the latest-and-greatest text
when saving, instead of relying on the handler for the "change" event.

This only occurs in the comment dialog.

Reviewed at https://reviews.reviewboard.org/r/6457/
Allow users to opt-out of their own updates.

Add `should_send_own_updates` field to Profile model. This field determines
whether or not the user should receive email updates about their own activity,
such as submitting review requests, reviewing requests, or replying to review
requests. The default value for this field is `True`.

Add an evolution, `profile_should_send_own_updates`, to add the same field to
the Profile model. This evolution sets the value for the field to the default:
`True`.

Add `should_send_own_updates` field to the Profile settings dialog. This field
is tied to the `should_send_own_updates` field on the Profile model.

Add `should_send_own_updates` method to the User model. This method is patched
on like the other methods in `accounts/models.py`.

The `send_review_email` removes the user sending the email from the set of
recipients  if they have their `should_send_own_updates` field set to False
unless they are one of the people assigned to the `people` field of the review
request.

Testing Done:
Ran evolution successfully.

Unit tests pass.

Tested with local development server. With `should_send_own_updates` set to
`False`, when a review request is created, that user only receives an email if
they are assigned as a reviewer (in the `people` field, not the `groups`
field).

Fixes bug 3316.

Reviewed at https://reviews.reviewboard.org/r/6429/
Merge branch 'release-2.0.x'
Fix double escaping on file attachment captions.

In review UIs, the caption text was getting double escaped. The reason for this
was that we used a template to dump it into javascript, which would escape it
once, and then called $.text(), which would escape it a second time. The fix
here is to use the escapejs filter when templating the value into javascript.

Testing done:
Created a file attachment with a caption that had some quotes in it, and
verified that the visible header in the review UI didn't have the literal
"&quot;".

Reviewed at https://reviews.reviewboard.org/r/6448/
Merge branch 'release-2.0.x'