Net::Bind::Utils
Make it a real module that exports functions. Reverted valid_domain back to the original version created by Kevin and renamed it valid_domain_rfc1035 because this functionality could still be useful for some applications. Created a new valid_domain function to determine if bind can actually resolve the domain.

Net::Bind::Resolv
Make /etc/resolv.conf the default when using new. Applied patch from Blair Zajac <blair@orcablue.com>: Improved and fixed the functionality of some issues including some methods where the values would be appended to the existing list instead of replacing the list. Allow comments to work for as_string().