When an Ether() / IP() packet is built with IP.dst set and Ether.dst
not set, Scapy tries to fix Ether.dst by sending an ARP request. This
fails when the user cannot send packets.

Before:

    >>> p = str(Ether()/IP(dst="1.2.3.4"))
    Traceback (most recent call last):
      File "<console>", line 1, in <module>
      File "/usr/local/lib/python2.7/dist-packages/scapy/packet.py", line 272, in __str__
        return self.build()
      [...]
      File "/usr/local/lib/python2.7/dist-packages/scapy/arch/linux.py", line 414, in __init__
        self.ins = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(type))
      File "/usr/lib/python2.7/socket.py", line 187, in __init__
        _sock = _realsocket(family, type, proto)
    error: [Errno 1] Operation not permitted

After:

    >>> p = str(Ether()/IP(dst="1.2.3.4"))
    WARNING: Mac address to reach destination not found. Using broadcast.

Accept generators and xrange objects as field values

Update setup files for PyPI

Use appropriate config value to call tcpdump

Move sebek to contrib/ (uncommon protocol)

Add PyPy to travis-ci tests

Fix .do_dissect() (code easier to read and a bit faster)

Update ethertypes link

Fix syntax for Python 2.5 compatibility

Remove unneeded lists (primarily range() calls)

Doc update for Github

gtp.uts fixed

Fix tests and test framework

Missing field import

This patch fixes test #28.

Fix ipsec layer to work w/ pycrypto lacking some AES modes

Fix PacketListField.do_copy() to work w/ strings elements

Add README / prepare for Git & Github migration

Fix EnumElement().get() (typo)