Add a stream field to the Blog model.

Set it to default to the blogging stream.  This can be configured to change the
stream to publish to.

FIXME: It should probably be an enumerate field.
Allow users to edit/delete their feeds.

Fixes #35.
Add missing index.html

Also,
- add a new filter for stream names
- minor changes to views based on the new index.html.
Add auto migration to the repository.
Split up the add and edit templates.
Show the hacker's name instead of the viewer's name.
Reorder and rename menu items
Rename template
Small UX changes and cosmetic adjustments
Fix showing 404 when requested profile does not exist.
Add a confirmation step before deleting blog.
Set the width of the edit blog url field.
Remove unused imports.
Update contributions list
Add instructions to make your account an admin
Merge pull request #64 from sursh/punchagan-edit-blog

Allow user to pick stream & edit their own blogs