Post-commit hooks now match repositories along with commit IDs.

When looking up review requests for a commit, we'd attempt to find one
that has a matching commit_id field if the commit description didn't
explicitly specify an ID. However, this lookup did not take the
repository into account, resulting in problems if two review requests
across two different repositories had the same commit ID.

This is not a major problem for Git and Mercurial. In theory, it could
affect Subversion on Google Code, but we actually have that matching
disabled (though we likely suffered from another bug as a result).

The repository is now passed to the matcher function, and is required
for commit ID matching.

Reviewed at https://reviews.reviewboard.org/r/6382/
Merge branch 'release-2.0.x'
Fix issue counter initialization with unopened issues containing states.

It's possible for a Comment to have both issue_opened=False and
issue_status=OPEN. We weren't checking for this during counter
initialization, resulting in such comments being included in the count.

The reason why they end up in this state is a separate issue that should
be addressed, but it's certainly easy to work around. We now properly
check the issue_opened field before even considering its issue_status.

There's also a fix for transitioning an issue status when saving the
Comment when issue_opened is False. This is needed for tests, primarily,
but would probably also solve some issues that could come up in the API.

Reviewed at https://reviews.reviewboard.org/r/6384/
Merge branch 'release-2.0.x'
Tweak intersphinx links.

This fixes our various links to point to https and use trailing slashes, and
makes our syntax consistent.

Reviewed at https://reviews.reviewboard.org/r/6381/
Fixed typo in example code for AuthBackendHook.

Changed "=" to "==" to compare instead of assign.

Testing Done:
Ran the code in a python script.

Reviewed at https://reviews.reviewboard.org/r/6386/
Merge branch 'release-2.0.x'