+++++
**Improvements**
- Added type() method to determine type of Directory (e.g. eDirectory, Active Directory): will be used later for type specific subclasses
- Added verify_password(dn, password) method
- Added escape_filter_chars() to filter (sanitize) the filter
- Override of cidicts __getitem__ so that user.attrs['nonexistent'] won't raise an exception, but instead returns an empty list