fully support private MathHubs

[kohlhase]

I have started experimenting with setting up my private MathHub instance.
Setup and configuration is really wonderfully easy and straightforward. But there are still problems.

• we have no library; see private mathhub no library #10
• configure should allow to choose a port
• we need a good way the admin can configure which archives are served.

[tkw1536]

Current status:

When starting a private MathHub, this brings it's own everything. On startup, it takes a couple minutes to pull the detault set of archives. If you want a 'private MathHub' the current way of doing it is installing the individual components, like the frontend.

[kohlhase]

yes, I tested that and it was impressively easy. But I want more :-)