Use Cloudinary URLs in content

[bhrutledge]

There are a number of Post instances with a body field that contains tags like <img src="https://www.hallelujahthehills.com/files/image.jpg">. These should be replaced with https://res.cloudinary.com/ URLs, via:

1. Uploading the image to Cloudinary, and using /image/upload/image.jpg
2. Uploading the image to Webfaction, then auto-uploading the image to Cloudinary using /image/upload/hth/image.jpg
3. Uploading the image to Webfaction, then fetching the image via Cloudinary using /image/fetch/https://www.hallelujahthehills.com/files/image.jpg

See Fetch remote images | Cloudinary for details on options 2 and 3.

Whatever workflow is chosen, it'd be nice to use the same thing for Release.cover_url, which currently relies on option 3.

It's probably easy to do this via an update queryset.