Add Outreachy Planet to Django site

[sagesharp]

Outreachy already has a planetaria at http://www.planeteria.info/outreach/. However, that has the following issues:

• Outreachy organizers need to manually add intern blogs and RSS feeds to the planetaria, and also to the Outreachy website. It makes no sense to manually add them in two places
• The planetaria is... fragile. Interns often try to hack together their own RSS feed generation, and sometimes that breaks planetaria, and the single maintainer is sometimes busy. Moving to a more widely used RSS toolset with more responsive maintainers would be good.
• The planetaria hosts both current intern blogs and alumni blogs. There's no way to filter to just the current interns, and the list of blogs in the right hand side is too long to easily scan. Having a way to filter for current interns, or all blogs for a particular Outreachy community would be good.
• The planetaria currently displays the full text of all blogs. This makes scanning for interesting topics hard. It would be good to (by default) collapse blog contents.
• Having the intern blogs hosted under the outreachy.org domain would aid search engine indexing.

This task has the following dependencies:

• We need to have a Django model for an intern, which includes their blog. This is the main gating task here, and it's something I want to define carefully.
• We need to have user accounts set up on the Django website, so that interns can edit their own blog and RSS URLs, so this eliminates the manual task of Outreachy organizers adding them.
• We need to set up a cron job on the Django server to pull down the contents of the intern blogs. There's probably good software for this already.
• We need to set up a Django package that takes the pulled down blogs, displays them in a page, and generates an RSS feed for that page.
• Bonus points if we can get different RSS feeds for different cohorts (rounds of interns) or all interns for a particular Outreachy community.

[sagesharp]

Daniel Pocock says: "If you get the blog URLs as part of the sign up then you could write a small script to extract them all from the database and generate planet.ini files

Virtual hosting multiple instances of the planet software is quite trivial, I already do this on a Debian host for some RTC planet sites. You just install the planet-venus package and create a different set of directories and a different line in crontab for each instance."