Camera Preview Display Works again

Got the camera preview display working again, Broadcasting still goes nowhere however. Investigated doing something with Chromecast but that plugin appears to be unsupported on Unity at the moment so it will be a while before that will happen, if ever. Fixed the ADSR help video and added the missing help video on the Air Horn. I also added the issue tracker to the repository so people can add issues they find, please review a little of what's there first to make sure I haven't already mentioned it before adding something.