 Version 7.0.0

* largely improved responsiveness and efficiency in episodes list with progressive building
* fixed strange appearance of horizontal dividers
* flattened Episode class, removed linked class EpisodeMedia, a major project structure change
* fixed player error dialog not showing
* added advanced audio quality tuning feature in PlayerDetailed view (Youtube media only)
	* a spinner to select locale (if any options)
	* a spinner to select codec (if any optioins)
	* a spinner to select bitrates (if any options)
* added ability to import DB from AntennaPod and Podcast Addict
	* most properties are transcribed
	* if imported feed exist in Podcini, relevant properties of the existing feed will be overwritten
