Werkzeug should use threading=True by default

[joeyespo]

The Django development server is multithreaded by default. Werkzeug is not, but you can enable it.

Django-devserver should mimic the default Django behavior and pass threading=True to run_simple (unless --nothreading is passed to runserver.)

[FlipperPA]

For the record, the --nothreading option is needed when using certain DB drivers that don't support multithreading. I'm looking at you, Microsoft: https://msdn.microsoft.com/en-us/library/hh568451%28v=sql.110%29.aspx