reference as an URI relative to
Returns the resolved URI.
The algorithm "Transform Reference" for resolving a reference is described in RFC-3986 Section 5.
Updated to handle the case where the base URI is just a relative path - that is: when it has no scheme and no authority and the path does not start with a slash. In that case, the paths are combined without removing leading "..", and an empty path is not converted to "/".
Uri resolveUri(Uri reference);