Using `~` as separator for SetCut elements. `;` is described as a reserved character inside a URI path component at [RFC2396](http://www.ietf.org/rfc/rfc2396.txt), and as a sub-delimiter at [RFC3987](http://www.ietf.org/rfc/rfc3987.txt), so it should not be used to separate SetCut elements. This issue is also discussed at https://github.com/DataBrewery/cubes/issues/13