added gitignore
Starting on netmap
User of PacketBurst could now set ownage of packet

When using packet bursts, the user of the class should set who is the owner of
the packets in the burst. With this API, default is unchanged (burst owns the
packets) but users could "disown" burst for packet memory management.
Corrected include path
Use 64-byte packet
NmNetDevice header implementation changed

Set headers before the sending (for performance). Corrected the private
implementation in respect.
Added an example packet generator
Rework FdNetDevice to allow subclassing
Fixed packet trace
Added the first part of receive side

Packets received from networks are added into a circular buffer of 1024
elements.
Added flag to not free buf in receiving
Code formatting
Added receiver part for netmap-cards
Useless pointer in nm-pktgen removed
Added an example receiver for netmap
Documentation
FdNetDevice members now protected
Removed circular buffer. Implemented a fdreader
New NmPktGen
New NmReceiver