fixed expr conn bug and added some deriv comp checking (making sure the right functions exist, etc.
merged with dev
fixing issue with replace, passthroughs, and nested configure calls
working on implicit tests
Merge branch 'deriv_error_check' of github.com:naylor-b/OpenMDAO-Framework into deriv_error_check
fix for Bret
removing bad test
Merge branch 'deriv_error_check' of https://github.com/Kenneth-T-Moore/OpenMDAO-Framework into deriv_error_check
fixed a couple more tests
cleanup
fixed doc test after accidentally unfixing it
fixing a test
Merge pull request #1575 from naylor-b/deriv_error_check

fixed a couple of bugs and added better checking for derivative API adherence.