Write docs for using ldapvi

[Baisang]

It's not clear how to do the following:

When updating DNS, apply your changes to LDAP, and then run make. It will rebuild the primary DNS (db.ocf) and reverse DNS, including pulling host data from LDAP and bumping the serial number.

i think the command is just ldapvi cn=lb or something?

[jvperrin]

Usually you have to do kinit $USER/admin ldapvi cn=<whatever>, yeah