LTI Gradebook items: allow grade calculations and release options to be configurable

Add the test tool like the one at www.tsugi.org/lti-test/ and add it as a content item producer.  Place an item into Lessons - make sture to edit the title each time you do this so you can find the right gradebook column.  There are two extensions on the same screen as the title  - here are the keys: https://www.sakailms.org/spec/lti-ags/v2p0/releaseToStudent https://www.sakailms.org/spec/lti-ags/v2p0/includeInComputation Each can be true or false (just enter these strings) and they set the default for the release and include checkboxes in the Sakai gradebook.  Each time you add an item - check the resulting gradebook column to make sure the checkboxes reflect the settings in the content item. Test this in both the direct link to the tool in Lessons and in a rich text editor in Lessons through the shopping cart.  Both should correctly set the checkboxes.