The Mix Bus Plugin Manager 0.2.2

Release notes render inline again — Fixes a problem with where Plugin Manager looks for a version's notes, so the detail pane fell back to "Open online" instead of showing them. Plugin Manager now reads the notes location straight from the update feed, so it stays put no matter how downloads are tracked.

fixes caching issue — in addition to the the 0.2.1 release we have now fixed a release notes caching issue so that the updated plugin manager displayes the latest release notes.