Allow uniqueVersion as deploy:deploy parameter or altDeploymentRepository field

The altDeploymentRepository property allows the id, layout and URL of a repository to be overriden.

However it does not allow the uniqueVersion setting to be overriden.
This reduces its usefulness as an override mechanism.

Patch implements the feature by using one of the spare fields in the property:

id::layout:uniqueVersion:url

e.g.

id::layout:true:url
id::layout:false:url
id::layout::url

If the value is empty, it defaults to true, as per the previous behaviour.