Add ability to deprecate properties and parameters

[emirkin]

It appears that there is no way to deprecate a parameter or property in swagger spec. The deprecate: true statement applies only at operation level

[whitlockjc]

This is a duplicate of #524. (I know it's hard to tell by the issue subject but there is an explicit request in that issue to allow deprecating parameters and properties.)

[emirkin]

@whitlockjc you seem to have made a reference to current issue instead of another.

[whitlockjc]

Woops.

[whitlockjc]

Thanks for the update. It's a duplicate of #524. I crossed the streams.