Reduced memory footprint of FeedUpdateInfo objects. Those objects might stay around for a while and accumulate (up to BUFFER_COUNT_BEFORE_INSERT = 20 at the moment), so in order not to fill up the memory it's better to keep as little data as possible.
Previously ChannelInfo data was stored, causing ReadyChannelTabLinkHandler objects to be also stored uselessly (and those channel tabs contain prefetched JSON data which used ~700KB of memory).
The previous "main" tab is now just a normal tab returned in getTabs().
Various part of the code that used to handle channels as ListInfo now either take the first (playable, i.e. with streams) tab (e.g. the ChannelTabPlayQueue), or take all of them combined (e.g. the feed).