Up Next, playback speed, and safer imports

Podcast listening gets a queue, and switching readers gets safer.

• The mobile apps leave beta for the public App Store and Google Play
• Up Next lines up episodes, and the queue follows you across devices
• Play any show faster or slower, with optional autoplay
• The Now Playing view is redesigned, with speed controls in reach
• Imports show a preview before anything is added, and accept .xml files too