Refactored OpenProjectWorkOrder for new WorkOrder design. This entailed a...

Refactored OpenProjectWorkOrder for new WorkOrder design.  This entailed a change to Project::addToProject, which needed to call child WorkOrder's execute even if clean state.  Fixes #4735.

git-svn-id: http://subversion.wr.usgs.gov/repos/prog/isis3/branches/ipce_FY17-Sprint1@7545 41f8697f-d340-4b68-9986-7bafba869bb8