fix for test from assumed_default change to float
added default_value to passthrough trait metadata
framework_var for gradient option
Merge branch 'dev' of https://github.com/OpenMDAO/OpenMDAO-Framework into vartree_asmb_boundary
assumed default in int and enum
backed out some changed to driver from another branch
added assumed_default to bool
merged out
Merge branch 'dev' of https://github.com/OpenMDAO/OpenMDAO-Framework into vartree_asmb_boundary
don't exit
Merge branch 'dev' of https://github.com/OpenMDAO/OpenMDAO-Framework into vartree_asmb_boundary
Merge pull request #1654 from crobinsonut/vartree_asmb_boundary

marking of traits with assumed default values