Update example and documentation to use with mobile devices

[darioodiaz]

To use userMedia on mobile devices you must use https/ssl server so, the broadcaster file must be on https connection, update the example and add it to the documentation for user that want to use it on mobile devices.

[carterbryden]

Chrome in general now needs SSL for a number of the more advanced features like webrtc, not just mobile.

[kbbqiu]

@darioodiaz Will do. We haven't optimized for mobile yet due to #26

[darioodiaz]

Ok, I keep testing that to see if I can help on that issue :)