Clean up headers.

don't expose symbols of ava helper routines

improvements to monitor backend: added a log entry that lists the current log level and can be modified via protocol at runtime, to change the log level; minor improvements; fixed a problem in dealing with dn normalization

now dnValidate loops thru each value; added private member to LDAPAVA to hold the attribute description

liberally accept many LDAPv2/LDAPv3 stuff in DN (quoted parts, ';' as rdn separator and so); enforce exact case match of normalized dn in dnMatch (let's see what happens ...); fix a ldapava_free_rdn bug

reimplement dn_validate/normalize/(match) using the ldap_str2dn/dn2str stuff; need to #define USE_LDAP_DN_PARSING

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Copyright 2001, Igor Khavkine, All rights reserved.
This is free software; you can redistribute and use it
under the same terms as OpenLDAP itself.

moved rdn parsing in a dedicated routine, ldap_str2rdn(), that can be used directly; now ldap_rdn2str() handles all the formats

may need optimization;
uncomment #define USE_LDAP_DN_PARSING in libraries/libldap/getdn.c
to enable its use.
The ava/rdn/dn handling routines (append, insert, free and so) must
be made available thru declaration in some header.

skeleton of ldap_str2nd/dn2str; works with most of the simple cases, but there's much to do with unicode, I think