Get rid of WebKit in favor of RTMP.

This patch removes WebKit in favor of RTMP to support a wider variety of clients. This patch also includes many HTTP request optimizations which results in an overall faster and more efficient plugin.

It's a known issue that this plugin is having problems streaming in Plex/HT beta, however, all of the other clients work as expected. We are working diligently with the Plex devs and community to track down the issue.