Sync implementation for subscriptions, tracking subscription removals, add fcast link to cast tutorial description.

Sync protocol

See merge request !35

This reverts commit 8c4e5118

Allow configuring stability threshold time and ensure there is no more than 1 job active at a time for SimpleOrientationListener.

Moved Autoplay button to top and load recommendations now appropriately uses 'StatePlatform.instance.getContentRecommendations(v.url)' for local videos.

Added rotation zone setting allowing you to specify the rotation to be less sensitive (default 45 degrees). Added reverse portrait setting allowing you to allow reverse portrait (default off). Added setting to hide recommendations.