Implement DIAL support.

DIALfor DIscovery And Launchis a simple protocol that 2nd screen devices can use to discover and launch apps on 1st screen devices.

This will be used for apps running on 2nd screen devices (Tablet, Phone, etc.), to be able to launch content on 1st screen devices (the media directors, in this case.)

The intent here is to create a DIAL device that runs on each media director, that provides a gateway to allow DIAL enabled apps (currently, this will be YouTube) to be able to send their content to the media director's TV.