Remove useless multiple podcast update methods
Remove multiple episode update methods
Remove unused SearchKeywordDb class

This also allows us to remove the dangerous getEpisodesWhere method,
which bypassed our episode cache completely.
Remove all references to PodcastDAOImpl.i()
Shorten singleton retrieval code lines
Split podcast DAO into a simple dao & caching decorator

This was the original intention.
Remove all references to EpisodeDAOImpl.i()
Remove duplicate db methods from assistant classes
Split episode DAO into simple & caching classes
Reformatting and TODOs in SimplePodcastDAO
Ensure tests start with a clean DB
Fix a local delete testcase

Locally deleted podcasts do not return the same Podcast object instance.
In fact, I'd like to redo the entire local actions concept.
Remove old TODO
Remove PodcastDBAssistant
Remove EpisodeDBAssistant
Make GUIUtils a pure static class
Add a TODO file with major refactoring tasks
Move playlist and episode action DAO instances to singletons
Remove unused ui test imports
Remove unused http download code