Mark which version something was deprecated in

[scop]

Describe the feature/solution

• note "deprecated in" bash-completion version in @deprecated comments
• add new parameter to _comp_deprecate_func to specify the "deprecated in" bash-completion version (could use this in warning messages if we ever start to emit them)

Originally from #870.

Maintenance (please complete the following information)

• This is a request for new completion
• Link to upstream project query about shipping the completion:

[scop]

Deprecation comment could be like @deprecated VERSION commentary here. I made #961 do that.