Support response files

[patriksvensson]

Discussed in #9

The OpenCLI specification needs to have a way of knowing that an OpenCLI description for an application supports response files.

This should be documented in the Conventions Object as an optional boolean supportsResponseFile: bool?.

[cmcgee1024]

Response files can have different escaping and quoting methods. Those should probably go in the conventions object too.

Also, response files might only be available for certain options, so there should probably be a supportsResponseFile on options too so that it can be set on each.