Interstellar updates: microblogging, YouTube embed, and image view

Features

• Add initial microblogging support, including viewing posts, voting/boosting posts, and replying to posts (thanks @olorin99).
• Add support for YouTube video embedding.
• Show detailed image screen (with pan/scale) when the thread image is clicked on.
• Add WebView option when opening links on supported platforms.

Here's the latest downloads

Also, please check out this thread for an icon design someone made for Interstellar.