[TLS] Unify UTCTimeField (small)

Replace the UTCTimeField occurences (one in ppi_geotag.py, one in dhcp6
and one in tls/handshake) by a single one

[Python 2 to 3] Remove longs and fix octals

[coverage] New tests to avoid randomness of coverage

[SCTP] RFC 4895 & 5061

Fields/BitField: implement .i2len()

[coverage] Small tests

to reduce the randomness of coverage

EAP - fix variable length field computation

[Routing/Windows] Improve routing system

add bindings for NSH over GRE

Updated/fixed install doc

Added some pipe objects

Signed-off-by: Gabriel Ganne <gabriel.ganne@enea.com>

[rewritten] PR #280

[coverage] Answering machines unit tests

[coverage] More tests for scapy/*.py files

Display IPsec field in hexadecimal

[coverage] Fix codecov results

Added link to 64bit Python version and added remark that pyreadline and Python should both be 64bits or 32bits.
(Also now link to Python 2.7.13 instead of 2.7.12)

To increase usability, display string field in hexadecimal.

Signed-off-by: Thomas Faivre <thomas.faivre@6wind.com>

Smaller unit tests results

* Code cleaning, unit tests
* Fix manuf DB path
* Specify seed in volatile objects using RandomEnumeration
* pypy fixes