Patched in SNMP trap code

Added new environment variables and dependency on snmp4j.

export SNMP_HOST="x.x.x.x"
export SNMP_PORT="162"
export SNMP_COMMUNITY="snmp_trap_community"
export SNMP_OID="trap_oid"
Fix dependencies for #163

Add osnmp.net repository for snmp4j
Merge pull request #165 from scobal/mpcathey-master

SNMP notifications (courtesy of mpcathey)