Make shift, setOrigin, and setCenter take either (x,y) as before or a PositionI parameter
(#380)
Enable the image.index_convention option (default 1)
(#380)
Add unit tests for new index_convention option
(#380)
Fix bug in return type of NFWHalo.getShear when input is a PositionD
(#380)
Fix bug in how I was using setOrigin in config.
(#380)
Add setOrigin to demo11.py and index_convention to demo11.yaml
(#380)