Remove errno from dav_error interface. Calls to dav_new_error()

and dav_new_error_tag() must be adjusted to add an apr_status_t parameter.

Reviewed by: jorton


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@882274 13f79535-47bb-0310-9956-ffa450edef68