minor mod_auth_basic and mod_auth_digest sync. mod_auth_basic

now populates r->user with the (possibly unauthenticated) user,
and mod_auth_digest returns 500 when a provider returns
AUTH_GENERAL_ERROR
Reviewed by:	justin


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@102719 13f79535-47bb-0310-9956-ffa450edef68