Add help string on how to configure multiple DNS forwards for various cli tools

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>

install/tools/ipa-dns-install

@@ -47,7 +47,7 @@ def parse_options():
                       default=[], action="append",
                       type="ip", ip_local=True, help="Master Server IP Address")
     parser.add_option("--forwarder", dest="forwarders", action="append",
-                      type="ip", help="Add a DNS forwarder")
+                      type="ip", help="Add a DNS forwarder. This option can be used multiple times")
     parser.add_option("--no-forwarders", dest="no_forwarders", action="store_true",
                       default=False, help="Do not add any DNS forwarders, use root servers instead")
     parser.add_option("--reverse-zone", dest="reverse_zones",

install/tools/ipa-replica-install

@@ -109,7 +109,7 @@ def parse_options():
     dns_group.add_option("--setup-dns", dest="setup_dns", action="store_true",
                       default=False, help="configure bind with our zone")
     dns_group.add_option("--forwarder", dest="forwarders", action="append",
-                      type="ip", help="Add a DNS forwarder")
+                      type="ip", help="Add a DNS forwarder. This option can be used multiple times")
     dns_group.add_option("--no-forwarders", dest="no_forwarders", action="store_true",
                       default=False, help="Do not add any DNS forwarders, use root servers instead")
     dns_group.add_option("--reverse-zone", dest="reverse_zones", default=[],

install/tools/ipa-server-install

@@ -282,7 +282,7 @@ def parse_options():
     dns_group.add_option("--setup-dns", dest="setup_dns", action="store_true",
                       default=False, help="configure bind with our zone")
     dns_group.add_option("--forwarder", dest="forwarders", action="append",
-                      type="ip", help="Add a DNS forwarder")
+                      type="ip", help="Add a DNS forwarder. This option can be used multiple times")
     dns_group.add_option("--no-forwarders", dest="no_forwarders", action="store_true",
                       default=False, help="Do not add any DNS forwarders, use root servers instead")
     dns_group.add_option("--reverse-zone", dest="reverse_zones", help="The reverse DNS zone to use",