Support NTLM authentication

[nils-a]

For people still stuck in the old world, it would be really nice if NTLM would be supported as authentication.

[AnWeber]

Hi, I can implement the function. But I would need some help. Firstly, I don't know the correct way to do NTLM and a test of the function at the end would also be helpful as I can't perform such a test. Would it be possible for you to support me?

[nils-a]

I have never implemented NTLM, either. But I'm certainly willing to help.
Doing some tests is not a problem.