Entry handler for multi-lingual attributes

[dfish3r]

Add an LdapEntryHandler that aggregates an attribute with all it's subtypes using the ;lang- option.

cn: Daniel Fisher
cn;lang-ru: Даниэль Фишер

would result in

cn: Daniel Fisher
cn: Даниэль Фишер

with the lang attached to the ldap attribute value at metadata.

See:
http://www.ietf.org/rfc/rfc2596.txt
http://www.openldap.org/lists/openldap-devel/199904/msg00038.html
http://www.ietf.org/rfc/rfc2251.txt section 4.1.5