The man pages for various FreeIPA setup tools are more descriptive on how to
configure multiple DNS forwarders than the corresponding cli help. This patch
makes the cli help more verbose now for the following tools:
* ipa-dns-install
* ipa-replica-install
* ipa-server-install
https://fedorahosted.org/freeipa/ticket/4465
Reviewed-By: Martin Basti <mbasti@redhat.com>