Replace when.js promise shim with rsvp since there are subtle differences
Replace when.js promise shim with rsvp since there are subtle differences

Would like to work those out and use when.js shim, since we don't need
the entire RSVP just for the Promise object.

nathanboktae/cherrytree,QubitProducts/cherrytree,QubitProducts/cherrytree,nathanboktae/cherrytree