Missing json import

Missing json import
Moved handling of rss_mode to within the update_rss function
Renamed rss_* variables to feeds_*
Renamed feed_* variables to feeds_*
Renamed update_rss to update_feeds
Fixed feeds_mode to have a default of 1 (enabled)
Fixed issue where playlist feeds were not created at start time
Added ability to disable playlist feed output
Added <playlist> tag to feeds options (1=output,0=suppress,default=1)

Signed-off-by: achbed <github@achbed.org>