Add new hook 'collection_add_media'
Start for documenting core hooks.

This is basicly a start by Chris Webber, I'm just commiting
it for him.
Add docs on collection_add_media hook.
List blogs by URL user rather than request user

The blog_post_listing function in mediagoblin/media_types/blow/views.py
attempts to access blogs based on the requesting user rather than the url
user. This results in server errors when an unauthenticated user attempts to
follow a link from another user's blog post listing, and 404 errors when an
authenticated user attempts to follow a link from another user's blog post
listing.

This change bases blog post listings on the URL user rather than the request
user.
Make blog_post_listing easier to read

This is Elronds change on #948. As 'blog_slug' is always
set in request.matchdict there is no need to do a default-none
get on the dictionary. This change just makes it easier to read.
eek, should be python2 not python22
Updating the AUTHORS file for this release
updating ayleph to Andrew Browning
Blog media type doc
not yet, anyway.
Updating release notes.
Committing present MediaGoblin translations before pushing extracted messages
Committing extracted and compiled translations
At version 0.7.0, at last!
Also add git submodule init to the release docs
Run the following to fix the missing git submodule init step
Correcting, host-meta not webfinger.
now in the 0.7.1.dev cycle
Raw image mediatype had a non-unicode logging call

Was causing UnicodeDecodeError when file/folder was not ascii.
Fixes bug #935.
Add __repr__ for Collection and CollectionItem