Request: add A/V requirements to talk proposal form

[wolever]

It would be helpful for A/V planning to have two new inputs on the talk proposal form:

• A check box: "[ ] This talk includes audio from a laptop or other device"
• A text box asking "Does this talk include physical elements (ex, robots, hardware devices, musical instruments, etc), or do you have any other special requirements that the AV team should be aware of?"

And please make sure these fields are also reflected in the API.

Thanks!