Re-enable ldapi code in ipa-ldap-updater and remove the searchbase
restriction when run in --upgrade mode. This allows us to autobind
giving root Directory Manager powers.
This also:
* corrects the ipa-ldap-updater man page
* remove automatic --realm, --server, --domain options
* handle upgrade errors properly
* saves a copy of dse.ldif before we change it so it can be recovered
* fixes an error discovered by pylint
ticket 1087