Store less.min.js as a static file

While developing locally, pages do not render correctly when there is no
Internet connectivity. This happens because LESS' pre-processor is being
loaded off the internet rather than as a static file (like other JS
files).

To make sure LESS works without Internet connectivity, store a static
copy and referene that in the JS pipeline instead of loading it
remotely.

Testing done: Tested manually in browser and everything worked.
Reviewed at http://reviews.reviewboard.org/r/3585/
Add review-ui URL field to FileAttachmentResource.

In order to properly link to the review UIs when adding file attachments through
javascript, I need to have a URL. If the given attachment doesn't have a review
UI, this URL will just be an empty string.

Testing done:
Set a breakpoint in the javascript that runs after a file attachment succeeds
and looked at the resulting object.

Reviewed at http://reviews.reviewboard.org/r/3576/
Fix fallback mimetype handler.

One small issue crept in with some of the recent changes to add new handlers for
additional mimetypes: if a type didn't have a handler, it wouldn't fallback to
the generic one. This meant that uploading files without handlers would generate
errors trying to get things like the icon url or the screenshot.

Trivial fix.
Merge branch 'release-1.7.x'
Tweak file attachment styles a little bit more.

This change does some small tweaking to the file attachment styles, mostly with
regards to the placement and scaling of the thumbnail images within their
container.

Reviewed at http://reviews.reviewboard.org/r/3586/
Fix some pyflakes warnings.

There's still a few minor ones left, but this removes the bulk of the
ones introduced, which largely had to do with unused imports. This
should reduce loading times just a little.
Merge branch 'release-1.7.x'
Use local_site_reverse in the admin UI.

We were using a standard reverse() call in the admin_subnav tag, which
wasn't factoring in LocalSites. Now all entries use the LocalSite
properly.
Use the URL names for pages in the admin UI, and don't hard-code.

The admin UI was hard-coding URLs for various pages under the System
Information sidebar. This broke subdirectory installs. We now use URL
reversing instead.
Add the 'basedir' field to the DiffResource fields.

This adds the 'basedir' field, which is used for determining the prefix
directory for paths in a patch, to the DiffResource payload. It's
particularly useful on Subversion in order to determine where a diff was
generated from within the repository.

Reviewed at http://reviews.reviewboard.org/r/3593/
Merge branch 'release-1.7.x'
Added the beginnings of the 1.7.0 release notes.

This will be added to up until the release.
Merge branch 'release-1.7.x'
Fleshed out more of the release notes.

This brings it up-to-date with the latest changes since RC, and fleshes
out some of the descriptions in some sections.

It also fixes a few structural problems in the release notes.
Fill in the description of the basedir field a bit.
Update Extension.__init__ doc examples to list *args, **kwargs.

Our extension docs weren't showing the requirements for *args, **kwargs,
which are needed as of 1.7 RC 1. List them in all the examples.
Rewrite file attachment javascript templating.

When uploading file attachments through the web UI, the box shown on the page
would be created from javascript instead of from a django template. The code
that did this wasn't quite at parity with the html that was generated when
loading the page to begin with. Most annoyingly, it didn't have a link to the
review UI (if one existed). It also didn't do any of the new caption stuff that
I added.

The code now uses _.template for the full case, and simplifies the placeholder
case (and fixes it to actually contain a spinner).

I'm also going to sneak in a fix for text-ish file attachment styles.

Testing done:
- Uploaded a bunch of files, both through the "Add file" dialog and DnD.
- Verified that the "Review" link was correct when there was a review UI.
- Checked that the generated HTML was the same as when reloading the page.
- Commented out the code that replaces the placeholder and verifiend the
  appearance of the spinner.

Reviewed at http://reviews.reviewboard.org/r/3587/
Merge branch 'release-1.7.x'
Added thumbnail rendering for XML file attachments.

This adds a Pygment-based renderer for XML file attachments.

Reviewed at http://reviews.reviewboard.org/r/3567/