Add orientation and shift to Port.__init__
Add orientation and shift to Port.__init__

This functionality makes it so that you can change the orientation of a
port on construction. You can also shift the port along the orientation.
This makes it cleaner to add a port that is offset from the anchor
(e.g., you can do it with 1 line istead of 2).

summeraz/mbuild,ctk3b/mbuild,iModels/mbuild,iModels/mbuild,summeraz/mbuild,ctk3b/mbuild,tcmoore3/mbuild,tcmoore3/mbuild