make ALLOWED_HOSTS configurable

[haraldschilly]

Add a command line switch to mathicsserver to add domains or even '*' to the list of ALLOWED_HOSTS in Django's settings. e.g. mathicsserver --domain foo.com → ALLOWED_HOSTS=['foo.com']

I know this is risky in general, but if there is additional authentication around the service, it isn't a problem.

Also, this is closely related to #771, i.e. to make it possible to host mathicsserver on a remote service, where authentication controls access and it can be accessed with a certain prefix in the URL.

[rocky]

Mathicsserver and more generally Django-based controls have been split off from this repository. See https://github.com/Mathics3/mathics-django.

In fact we are not really working in this repository much anymore. Core items (Built in functions and item not related to front-end processing or back-end rendering) are now handled in https://github.com/Mathics3/mathics-core.

[haraldschilly]

oh, I see! so, this ticket and #771 should move over there.