check for preSubmit errors
check for preSubmit errors

Solves #200.
TODO: error bubbling.
braincrafted/bootstrap-bundle,bigfoot90/bootstrap-bundle,althaus/bootstrap-bundle,lashus/bootstrap-bundle,althaus/bootstrap-bundle,bigfoot90/bootstrap-bundle,lashus/bootstrap-bundle,braincrafted/bootstrap-bundle,lashus/bootstrap-bundle,braincrafted/bootstrap-bundle,bigfoot90/bootstrap-bundle,althaus/bootstrap-bundle