Data::Traffic: 10G traffic support

Increments the maximum bytes.
Data::Iferr: add the collector for the ifDiscards and the ifErrors

This module can collect the errors and the discards on the network
interfaces.  This can be used by specifying iferr:<ifname> as the
resources into the host_config.
Data::Udp: add the collector for the UDP counters

This module can collect the UDP counters: udpInDatagrams,
udpOutDatagrams, udpInErrors and udpNoPorts.  This can be used by
specifying "udp" as the resources into the host_config.
Data::Iferr: add a test case

Add test case for the module loading.
Data::Udp: add a test case

Add test case for the module loading.
Merge pull request #35 from atzm/features

Features
Fix bug that failed to get all basic metrics with net-snmpd 5.5 or 5.6
Merge pull request #37 from hirose31/fix/cpu-steal

Fix bug that failed to get all basic metrics with net-snmpd 5.5 or 5.6
Treat ssCpuRawSteal as unknown value instead of 0 w/ snmpd < 5.7
Merge pull request #38 from hirose31/fix/cpu-steal-undef

Treat ssCpuRawSteal as unknown value instead of 0 w/ snmpd < 5.7
Fix comment
Merge pull request #39 from niku4i/fix_comment

Fix comment