POE interface to Net::SNMP

POE::Component::SNMP is a POE-ized wrapper around the the Net::SNMP module.
Most of its arguments aren't even evaluated by POE, except for -alias and
-callback_args, as described in the manpage.

If you want to make non-blocking calls with Net::SNMP in a POE application,
this is the module to do it with.