Add SNMP event callback for error notification

Added callback support for SNMP events.

Parse the callback message and raise SNMP trap

Clients specify the object paths to watch and callbacks
to invoke in the config yaml.

Change-Id: I105652f65e4e1c5354c934c88e4d59866540f71c
Signed-off-by: Marri Devender Rao <devenrao@in.ibm.com>
diff --git a/src/Makefile.am b/src/Makefile.am
index e5827e6..23c6009 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -12,7 +12,8 @@
 	propertywatch.cpp \
 	resolve_errors.cpp \
 	event_manager.cpp \
-	event_serialize.cpp
+	event_serialize.cpp \
+	snmp_trap.cpp
 
 phosphor_dbus_monitor_LDADD = \
 	$(SDBUSPLUS_LIBS) \