[turba] Attribute types

[Feczak Szabolcs]

Which are the valid attribute types other than
email, multiline, phone, text

I would like to have enum or checkbox as in main horde
config files, but it does not seem to work.

This is needed to represent the HTML/Plain text field
in ldap for mozilla. The schema defines a syntax that
the field has to be either TRUE or FALSE, but entering
these values by hand into a textbox is not too user friendly.