Refactor ldap_mod_attr and ldap_replace_attr:
- Remove the nebulous 'args' and .split() 'magic'
- Make the object to be acted on explicit
- Attribute values are now used 'verbatim'.
- Value construction (e.g. with buildDN()) is now done at list creation time
Update do_ methods to reflect these changes
Add support for netgroup operations:
- do_member adds netgroups as members of netgroups
- do_triple adds triples to netgroups
- inheritance of add/delete/etc as per group and other methods