New function: bind_check_hostname
New function: bind_check_hostname

This function is called from the default-record.erb in order to validate
each entry. This way, we can prevent bind configuration error.

ccin2p3/puppet-bind,cyrus-mc/puppet-bind,mvisonneau/puppet-bind,mcanevet/puppet-bind,raphink/puppet-bind,ccin2p3/puppet-bind,interlegis/puppet-bind,camptocamp/puppet-bind,raphink/puppet-bind,camptocamp/puppet-bind,trovitsys/puppet-bind,cyrus-mc/puppet-bind,mvisonneau/puppet-bind,cloudbuy/puppet-bind,interlegis/puppet-bind,mcanevet/puppet-bind,cloudbuy/puppet-bind,trovitsys/puppet-bind