Initial work on new feed parser
Model: Don't purge episodes after update
Podcast Parser: Remove obsolete function
Podcast Parser: Text data supplied in end() function
Podcast Parser: Simplify path matching
Podcast Parser: Mini Test Framework, Refactoring
Podcast Parser: Update existing episodes, refactoring
Podcast Parser: Supply channel object to handler function
Avoid unnecessary feedparser imports
Podcast Parser: Simplifications and refactoring
Podast Parser: add_episode and validate_episode
Podcast Parser: Prefer Audio over Image enclosures
Podcast Parser: Enclosure "rating" function
New test case: Item with no enclosure