add filtering support of infeasible(None) objective value
add constraint filtering support of paretofilter and add constrained example of single_objective ei with constraint
minor error modifications
Merge remote-tracking branch 'origin/dev' into dev
Merge remote-tracking branch 'origin/dev' into dev
Merge pull request #1736 from naylor-b/dotgraph

fix to remove extraneous pseudocomps from a workflow
Merge remote-tracking branch 'origin/dev' into dev
test works
Merge pull request #1721 from cwmine/dev

add constraint filtering support for paretofilter and modified constrained  single_objective_ei to test it
trying to group nodes by workflow - not really working yet
Yet another fix to VariableTree copying...
Merge pull request #1739 from setowns1/bug

Yet another fix to VariableTree copying...
fixed invalidation problem with vartree input as src
updated test for vtinput as src invalidation issue
Merge pull request #1740 from naylor-b/insub_bug

bug: vtree input as src was being improperly invalidated when it had no upstream connection
Merge branch 'dev' of github.com:OpenMDAO/OpenMDAO-Framework into dotgraph
tweaking component graph plot with workflows