Preselect "Audience" if passed project nid is an OG

Currently, if you do OGs as Project, you still have to manually click the group/project from OG's Audience checkboxes. We should, just like Project preselection, look at node/add/CASE/PROJECT_NID, find out if PROJECT_NID is an OG and, if so, pre-select that in the OG box. This will streamline the process a bit more.