[Zope-PAS] Proposed challenge implementation

[Lennart Regebro]

Zachery Bir wrote:
  > We should probably have a default case where PAS either always emits 
the
> Basic Auth challenge, or lets the ZPublisher do it, don't you think?

Well, in this case, when unauthrized is called, if nothing is raised by 
the plugins, the default unauthorized "raise Unauthorized, m" exception 
will happen.

> Got any tests? 

Not yet, but I'll try to get some in there.