Add ha1 based digest auth. Allows the admin to save passwords in digest ...

[ambitslix]

Hello,

I think digest based api should be helpful since token digests are more secure to store. This is how it's done for Apache and Nginx also. I've also created a tool to ask for passwords and save them in a file as "realm:user:token" entries that can later be loaded at startup time. It would be nice to have a connection_context available in the api so that we don't have to search a database for tokens every time authentication is needed on the same connection/request?