Remove unecessary call to GridView.p.resetRows() in .initialize()
Avoid using the same 'data-uuid's for row items as the items they are holding
Allow things that override GridView.p.sortableOptions to provide their own stop callback
Merge branch 'feature/issue-408-basic-dynamic-grid-layout' into develop-frontend
Add forgotten go.components.model.Model tests
Merge branch 'develop-frontend' into feature/issue-381-basic-dialogue-screen-state-layout