growl notifications cause excessive delays when configured with non-resolvable hostname
When growl notifications are configured to go to a hostname, and that hostname doesn't resolve, it causes a 1 minute delay in notify_via_growl(), from the fsockopen in growl.class taking that long to timeout. The timeout parameter to fsockopen doesn't apply to its DNS queries, so doesn't help there.
Don't call growl if the configured address isn't an IP or resolvable
hostname. Avoids 1 minute timeout delay in fsockopen in growl.class. Cuts
that down to about a 20 second timeout. Ticket #4739