Have the Capsd collector skip the 64-bit counters in IfXTable

The Capsd interface collector tries to retrieve the ifXTable in its entirety, even though it appears to use only ifName and ifAlias and discard the rest. When this collector encounters an SNMPv1 agent that responds for these counters (ifHCInOctets, etc) in violation of RFC2576, SNMP4J correctly discards the illegal response PDUs, and the node's interfaces don't get populated into the database.

On my system running 1.6-testing at r10267, I ripped out these 64-bit counters from IfXTableEntry.java and adjusted the values of NUM_OIDS and each of the constructor calls in the init block. With this change, I successfully discovered a v2c agent and all its interfaces, and data collection of the high-speed counters is working perfectly. This is the case with both the SNMP4J and JoeSnmp strategies.

Note that this change will only allow the interfaces to be discovered on agents that exhibit this bug -- once they're in the system, we will likely see data collection failures since the default configs specify trying to collect the high-speed counters regardless of agent version. By moving the buggy agents to their own collectd package that specifies an snmp-collection that excludes the ifHC* counters, we can get around that secondary problem.