For now both winpcap and npcap are supported with the latter being
experimentally supported till we get some feedback from users and
confirm that things are all working fine with npcap.
OID for link state has been changed to one that supports both.
To check which is being used, run 'drone -v'.
Fixes#236
Enable logs if '-d' command-line option is given.
Additional command-line options -
-v : print version
-h : print usage
Drone only:
-p <port-number> : use given port number for the RPC service