Add smartsnmpd.

smartsnmpd is an implementation of SNMP Agent developed by Credo Semi. It
use Lua as script language to write SNMP MIB nodes to improve the efficiency
of developtment.

This package add native support for OpenWrt. Include using ubus and uci to
get status/info. And, it use uloop as low level event library. So it's
some sort of desgin for OpenWrt.

Website: https://github.com/credosemi/smartsnmp

Signed-off-by: Leo Ma <leoma@credosemi.com>
Signed-off-by: Xiongfei Guo <xfguo@credosemi.com>

net/smartsnmpd/files/smartsnmpd.conf

@@ -0,0 +1,21 @@
+config smartsnmpd
+	option port '161'
+	option ro_community 'public'
+	option rw_community 'private'
+	option mib_module_path 'mibs'
+	option objectid '1.2.3.4'
+	option contact 'Me <me@example.org>'
+	option location 'Shanghai'
+	option services '72'
+
+config smartsnmpd_module
+	option oid    "1.3.6.1.2.1.1" 
+	option module 'system'
+
+config smartsnmpd_module
+	option oid    "1.3.6.1.2.1.2" 
+	option module 'interfaces'
+
+config smartsnmpd_module
+	option oid    "1.3.6.1.1"     
+	option module 'dummy'