How to use net-snmp api in XCode project.

Mac OS X includes net-snmp library by default, and how to use the net-snmp api in XCode is as follow.

1. Select a project on the right pane of XCode window.
2. Select "Build Phases", and open "Link Binary With Libraries".
3. Click "+" button, and add "libnetsnmp.dylib". That's it.