fixed broken tests after output_names merge
added utility function to close all connections to database
added tests for supplemental output results from simulation
added step attributes to number inputs for html5 validation. Fixes #44
removed conditional exclude from AirborneSpreadForm. appears to not be needed as code is in place to hide the field via javascript instead. Refs #44
Merge branch 'master' of https://github.com/NAVADMC/SpreadModel