Clean up the load_datatypes method in the datatypes registry. Make the code pep8 compliant. Only load sniffers if they have not already been loaded. Do not load sniffers for datatypes that are being deactivated. Refactor loading of datatype sniffers into its own method. Improve exception handling when loading datatypes.
Update the tool dependency installation process to mark a tool dependency as installed if the path exists, contains the installation log file, and app.config.running_functional_tests is True. This enables caching of compiled or downloaded tool dependencies when running the EC2 installation and testing framework.
Fix missing blast.py in blast_datatypes repository tarball for tool shed functional tests.