mod_auth_digest and updating the docs

[Wilfredo S�nchez]

The configuration for mod_auth_digest changed recently such that the AuthDigestFile directive no longer works. This is not reflected in the documentation, nor is it even mentioned in CHANGES that I can find.

Can we please make it a habit to do both of these when appropriate? All user-visible changes should be noted in CHANGES, and anything this significant should be updated in the docs.

Anyone working with HEAD has no straightforward way to figure out how to configure the module now, which is weak.

-wsv