sasl authz "dn:" type normalization (ITS#2852)

[ando@sys-net.it]

Full_Name: Pierangelo Masarati
Version: HEAD
OS: Linux RH
URL: http://www.sys-net.it/~ando/Download/slap-sasl-authz-regex-type-2003-11-30.patch
Submission from: (NULL) (81.72.89.40)
Submitted by: ando


When dealing with saslAuthz{To|From} attribute values,
in some cases the "dn:" type doesn't pass normalization 
because of regex special chars.  This patch introduces
a new type of saslAuthz* string, "regex:", which desn't
undergo normalization before being compiled in regcomp().

The present patch may break some existing configurations
and databases, because "dn:" type saslAuthz* attributes
are not considered regexp any more.  In my opinion,
the present patch clarifies an ambiguous issue, so "dn:"
type values should not be considered regexp any more.
However, for backwards compatibility, this statement
may be relaxed.

Ando.