Add Ability To Query SNMP OIDs Individually

Added a control to the SNMP check to allow for querying all of
the OIDs for a check separately. This fixes the issue where some
SNMP servers are not configured to handle bulk OID requests, as
well as the SNMP v1 issue where sending a single bad OID can
invalidate the entire request.
Add ganglia module
Remove changes to configure.in
Updated with postwait's changes
passive lua checks using coroutines with carbon example
Merge branch 'lua_passive'