The Features change broke all unit tests that deal with

SiteConfiguration. This happened because djblets.features, which

is put into INSTALLED_APPS, would import djblets.features.checkers,

which imported SiteConfiguration.
It's not valid for a module in INSTALLED_APPS to directly or indirectly

import a model. While this didn't actually break things in Django 1.6,

it does in 1.7 and higher, due to more strict behavior for model

loading. This import ended up preventing SiteConfiguration from being

properly synchronized to the database.
To fix this, the SiteConfiguration import has been moved into the

function that needs it.
There were also two other HTML-related failures.
1) There was a check in the conditions tests that broke due to the

   addition of newlines in generated HTML for one of the widgets we use.

   We now use assertHTMLEqual() to perform a more suitable check.
2) We allowed use of an older Pygments releases, but tested against

   newer HTML. We're now requiring a more modern version in

   dev-requirements.txt.

Unit tests pass against Django 1.6 and 1.8.