freshen the LDAP support

* Build the base DN from a given domain name
* Remove all hard-coded names to allow configuration of base DN
* Fix manager DN (cn=Manager,dc=...)
* Add ldap init_ldap()
* Add support for clean.sh

Change-Id: Ieb69be9740653645b8e000574ad3fe59a0f97540
diff --git a/files/apts/ldap b/files/apts/ldap
index 81a00f2..26f7aef 100644
--- a/files/apts/ldap
+++ b/files/apts/ldap
@@ -1,3 +1,3 @@
 ldap-utils
-slapd # NOPRIME
+slapd
 python-ldap