When using scapy as a third party library, we do not "benefit" from the
loading routine that puts all symbols in the __builtin__ namespace. This
implies that all modules must be "importable" without any errors for
undefined symbols.

This patch fixes importing every scapy module individually. Some
circular imports were fixed (between inet6 and dhcp6).

Most errors were detected by using pylint with the right configuration
(scapy produces a *lot* of errors). Other errors were detected with the
following shell script:

    export PYTHONPATH=".:$PYTHONPATH"
    for f in $(find scapy/ -name '*.py'); do
        f=${f%/__init__.py}
        module=$(echo ${f%.py} | sed 's,/,.,g')
        python -c "import $module; print $module"
    done

Also, replace all implicit relative imports by absolute imports to avoid
surprises with some python versions.

Signed-off-by: Robin Jarry <robin.jarry@6wind.com>

EAPOL / EAP updates and regression tests

Allow one to send the TCP User Timeout Option described in RFC 5482 in
a crafted TCP segment.
Also added unit tests in new "TCP options" section of
test/regression.uts

Insert DER test data inside x509.uts and move it from scapy/layers/ to test/ (also, remove obsolete X.509 tests from test/regression.uts

As suggested by @guedou, this adds tests for fragment() and
defragment() functions.

--HG--
branch : ICMPv6NDOptDNSSL fixes

--HG--
branch : Support for DNS Search List Option in RA

--HG--
branch : Patch for PR#115

--HG--
branch : Patch for PR#82

--HG--
branch : issue-5105

--HG--
branch : issue-5105

--HG--
branch : UTS fixes

Issues #884 & #915: IPv6 NA is not a NS & Error in class ICMPv6ND_NS(_ICMPv6NDGuessPayload, _ICMPv6, Packet):

Packet.build() is called only on the first layer. It will call
Packet.do_build() which will recurse through all layers. For each layer,
it will call Packet.self_build() which will do the job for each layer.
Packet.do_build() will call Packet.post_build() and transform on them,
and concatenate them. Then Packet.build() will call Packet.build_padding()
and Packet.build_done().

Note that this undetermined case will have a different behavior:
Raw("ABC")/Padding("abc")/Raw("DEF")/Padding("def")

It was "ABCabcDEFdef"
Now it is "ABCDEFabcdef"