Store task id in session to avoid cache timeout

Fixes Inboxen/website#179
Allow messages to be dismissed

Fixes Inboxen/website#89
Make edit/delete/important buttons more screen reader friendly
Do the same for pagination
Some numeric HTML entities had their leading "#" missing

[skip ci]
Add progress bar to "feeder" command

[skip ci]
CWD isn't always where we'd expect it to be.

These changes try to find the local git repo by working out where the current settings module was loaded from

[skip ci]
Revert "Store task id in session to avoid cache timeout"

This commit broke search

This reverts commit dea7fb8b3c169aa52304c88f06d64d2f371aed2d.
Fix search task disappearing from cache by re-setting it on api request
Backport ManifestStaticFilesStorage from staticfiles in Django 1.7

Please use {% static %} when linking to static content from now on.
Maintenance page is no longer static

It's now rendered as part of using the "collectstatic" command. That
should mean that it can be easily updated with our base template and
style sheets.

Fixes #4
Use simplejson as it has object_pairs_hook support Py2.6
Import staticfiles into search template
Collect static files before testing
Add --noinput to collectstatic command

We have no input.
Test for broken blog feed
Fix blog feeds
Fetch all headers if the user asks

Fixes Inboxen/website#118
Unit test raw header rendering
Proxy URLs in HTML emails

See Inboxen/website#159