Migrate feeds from Feedburner

[philgyford]

• Create new URLs for each of the four feeds (in addition to existing)
• Change links on site to point to them
• Somehow add an item to each of the existing feeds letting people know about the new URLs – maybe save the XML, manually add the item, save as templates, create new Views that render the templates with correct headers.

[philgyford]

Deciding to leave this one for now. If it still works, don't fix it.

If/when Feedburner is closed, maybe they'll offer the ability to redirect Feedburner URLs elsewhere, which they haven't offered since restricting its services. That would make migration to new URLs easier.