Description of problem: After setting up ipa trust, CLDAP plugin fails to start if IPv6 support is disabled in the kernel.

For example: 

LINUX...[25/Nov/2013:15:37:06 +0100] ipa_cldap_init_service - [file ipa_cldap.c, line 148]: Failed to create socket
[25/Nov/2013:15:37:06 +0100] ipa_cldap_init - [file ipa_cldap.c, line 207]: Failed to initialize CLDAP Plugin

Version-Release number of selected component : ipa 3.X

How reproducible: 100 %

Steps to Reproduce: NA


Actual results: Identity Management guide does not mention the requirement of having IPv6 support to use IPA AD trust


Expected results: Update the Documentation to include the IPv6 support on the machine to use IPA AD trust.

Additional info: 
snip from : https://www.redhat.com/archives/freeipa-devel/2013-May/msg00278.html

---------------------
Here is what we have in ipa_cldap.c:
   ctx->sd = socket(PF_INET6, SOCK_DGRAM, 0);
    if (ctx->sd == -1) {
        LOG_FATAL("Failed to create socket\n");
        ret = EIO;
        goto done;
    }

So we failed to create a socket using PF_INET6 family. It looks like you
don't have IPv6 enabled in your kernel?
--
/ Alexander Bokovoy

---------------------