OldAPI/url/ProposalK

/*** resolve
    returns the real, absolute, fully-qualified URL arrived
    at from a ``base`` URL following an relative ``rel`` URL.
    When no ``base`` is provided, resolves the ``rel`` URL
    relative to the current working directory.

    - accepts ``rel``
    - accepts an optional ``base``

*/

/*** relative
    returns the relative URL between two fully-qualifed paths.
*/