* Add a check_user_passwd() and a get_user_dn() functions in lib/ldap/functions.php3

* Add a check_user_passwd() and a get_user_dn() functions in lib/ldap/functions.php3
* Add general_restrict_badusers_access directive. If set to yes we only allow each administrator
  access to their own entries in the badusers table
* Add a username.mappings table. We are able to map each administrator username to additional queries
  on the accounting and user settings tables.
* Add an sql_accounting_extra_query directive. If set this query is included in all
  queries to the accounting tables.
  Combined with admin username mappings we are able to easily restrict access on specific accounting data
  to each administrator.
* Escape bad characters in the $login variable
* Add a da_sql_escape_string function. We use that for every element we pass to sql queries in order to
  protect ourselves from sql injection.
* Use the ldap_userdn directive where applicable in the functions.php3 file
* Add an sql_xlat function

TODO: Check out the sql queries in lin/sql for sql injection.