Use FQDN for a client name.

In the case where hosts have the same name, but different subdomains
we should use FQDN instead. Also, the Perl program driving the
configuration only accepts a max of 32 characters for a name.
truncate the name for the idempotency check as well
Merge pull request #5 from hw-cookbooks/fix/client-key-fqdn

[COOK-2740] Use FQDN for a client name