v0.52 Remote Server

I've added a remote server to this application so it is possible to trigger screenshots via a WebSocket connection, the screenshot result will be returned over the same connection.

A number of options are available in the interface and the payload specifications can be found in the documentation.

Also fixed a small issue where screenshots could in some cases be triggered when the SteamVR dashboard was up, which is pointless as at that point the scene application has a reduced render resolution so screenshots become miniscule.