Re-implement Podcast plugin

- make OPMLBased
- add custom XML browser
- add support for progress tracking: allow user to continue where he
left
Re-implement Podcast plugin

- pause progress reporting when playback is paused
- format time strings
Allow drilling down feeds
Re-implement Podcast plugin

Tweak custom podcast parser to fix ip3k browsing.
Re-implement Podcast plugin

Remove default streams - none of them was working any more.
Initialize settings module if web is enabled.
Re-implement Podcast plugin

The Podcast plugin is not being used on mysb.com. Remove some more code.
Re-implement Podcast plugin

Link to podcast stream managed on mysb.com.
Merge branch 'public/feature/podcast-v2' into public/7.8

Change-Id: I99e28a75aafa0134efcabfd9a6dc63930b390736