fix findByEmail searching for deactivated users
remove unused email attr constant

an accounts email address can be stored in either the cn or the uid, this means there isn't one
specific attribute to lookup the email address through. Every place we interact with the email
address has the cn/uid rules explicitly spelled out.
propagate along the includeDeactivated flag for consistency
Merge pull request #25 from GlobalTechnology/bugfix/findDeactivatedByEmail

fix findByEmail searching for deactivated users