ZXID: Changed arguments to authenticate().

Recent versions of the zxid library have an extra parameter "uri_path"
that they want from the request. To avoid needing to pass this argument
via enviroment variables, we now use some lower level functions.

Fixes "null or empty cgi->uri_path=(null) qs(...) programming error".
ZXID: Added configuration option "IPPORT".
ZXID: Added version().
release number bumped to 898 by export.pike
release number bumped to 899 by export.pike