disable promiscuous mode by default, fix tests.

By default promiscuous mode is disable and can be enabled with
--promiscuous.

Fixed the tests, since the order of the flags was backwards, the
most relevant flag will be shown first in the prin output.

Signed-off-by: Victor Palade <[email protected]>

initial functionality: Add interface sniffing.

Add functionality for sniffing a user specified device,
this will return the protocol TCP/UDP source and port
and destination and portm the TCP Flags and the size of
the packet.

Signed-off-by: Victor Palade <[email protected]>