[ANN] packetgen 2.1.4 released

packetgen 2.1.4 has been released.

* home: <https://github.com/sdaubert/packetgen>
* bugs: <https://github.com/sdaubert/packetgen/issues>
* doc: <https://github.com/sdaubert/packetgen/wiki>

PacketGen provides simple ways to generate, send and capture network
packets.

Known protocols are: Ethernet, Dot11, Dot1x, ARP, IP, IPv6, GRE, ICMP,
ICMPv6, UDP, TCP, SNMP, ESP, DNS, IKE and EAP.

Changes:

### 2.1.4 / 2017-11-11

* add support for EAP protocol (Header::EAP)
* Header::Base and Header::ASN1Base now implements a void callback
#added_to_packet. This callback is called when a header is appended to a
packet. This will help to customize a packet for given header,
* add Types::Int24, Types::Int24le and Types::Int24be. Use them in some
IKE headers
* add Header::Dot1x#calc_length
* Inpsect module: print human name for Types::Enum types
* Packet#to_w may now call #calc and send multiple
* update Header::Dot11 documentation

* Fixes:
** fix Packet#add_header: old implementation adds header methods to
class instead of instance
** Header::Base::Binding#set: make it works with header attribute
terminates with a '?'
** #to_w (all headers responding to it): close socket after sending packet
** fix Dot1x#read: nor more put ethernet padding in body