fix for warning
Merge pull request #1627 from Kenneth-T-Moore/dev

Fix for a warning about complex casting
Merge branch 'vtree_boundary' of github.com:naylor-b/OpenMDAO-Framework into vtree_boundary
Fixed my bug
fix on test
cache added
Merge branch 'vtree_boundary' of https://github.com/Kenneth-T-Moore/OpenMDAO-Framework into vtree_boundary