Update exabgp to version 3.4.7.

Most of our patches (mostly == for test in Bourne Shell) have been
integrated upstream.  Retain a more minimal fix to the healthcheck
script.  Add dependency on python setuptools.

The helper scripts of exabgp are now in share/exabgp/, to make
pkglint happy.

Upstream changes:

Version 3.4.7
* Package: be more pythonic and use enty points with pip installation
* Package: automatically update debian's changelog on release
* Fix: issue with aggregator generation
  reported by: Yan Filyurin

Version 3.4.6
* Fix: a badly formated flow route would throw the parser in limbo
    reported by: NickGudov (issue #203)
* Fix: allow multiple extended attribute (like flow rediction with a
  origin/target)
* Fix: use ICMP Type and Code when printing flows (respectively using
  name and number)
* Fix: do not use space printing redirect extended community
* Fix: not parsing correctly multisession configurations
* Fix: bug in ASPath parsing
    reported by: Terry Hardie (issue #205)
* Feature: use ETC environment variable for configuration location if set
* Feature: JSON now includes ASN (local,peer) and IP (local,IP)
    requested by: jtkdpu (issue #196)
    patch by: Ryan Tinianov (pull #199) for the IP
* Feature: API support for sending eor
    requested by: spakka (issue #109)
* Feature: allow routes to have a name (which can be used as comment)
    requested by: lazy404 (issue #167)
* Feature: improve release code to prevent version mismatch (issue #202)
    reported by: Anand Buddhdev
* Fix: systemd file is not installed anymore by default (issue #202)
    to add to the file installation list use "python setup.py install systemd"
    requested by: Anand Buddhdev
* QA: moved all testing code (used by travis-ci) in the ./qa folder
* QA: added nosetest, updating some of the old unittest code
* QA: integrated travis-ci with coveralls.io to have real time code coverage
* QA: ExaBGP can take more than one configuration file and on configuration
  reload rotate between them
* QA: checking that broken flows do not break the parser
* QA: checking that configuration routes are well added and removed on SIGUSR1
* QA: checking that incoming notifications are handled correctly
* QA: moved many sample configuration file from etc/exabgp to the new qa/conf

Version 3.4.5
* Fix: improper distribution of events to process workers
    reported by: Tim Epkes

Version 3.4.4
* Fix: bug with IPv4 / ipv6 handling
* Fix: better peer isolation when parsing messages
* Fix: IPv6 decoding when the routes includes link-local
* Fix: missing text API paramter
* Fix: no JSON for Aggregator
* Fix: show route extensive
    patch by: Michal Grzedzicki, thank you
* Fix: 4-Octet AS Specific BGP Extended Community (RFC 5668)
    patch by: Michal Grzedzicki
* Fix: bug with label encoding
    patch by: Jesse Mather
* Improvement: add support for add-path with family MPLS
    requested by: Tim Epkes
* Fix: bug when process writes multiple lines
    reported by: Ilya Voronin
* Feature: accept packet with confedation (RFC 3065)
    requested by: oriordan (with a patch, thank you)
* Fix: do not bark if an unknown ASPath attribute is found
* Fix: correctly accept connection on AF_INET6 socket
    patch by: John W. O'Brien
* Fix: restore lost python2.6 compatibility
    reported by: Minsuk Song
* Fix: IPv6 MD5
    reported by: Dave J Knight
* Add framework to debug SIGUSR1 related problems
* Fix: do not drop session when receiving an unknown capability
    patch by: Peter van Dijk (PowerDNS)

Version 3.4.3
* Fix: JSON message increment
    reported by: Daniel Neiter, with a patch, thank you.
* Fix: JSON message format for operational
    reported by: Rob Barnes, with a patch, thank you.
* Fix: JSON message for route-refresh
* Fix: EOR unpack issue
* Fix: ASPath encoding
* Fix: possible bad notify call
* Fix: Aggregator configuration issue
* Fix: pycharm reported issues
  * operational, using afi instead of safi
  * bad function paramters
  * missing return keyword
  * many cleanups
* Change: use RFC MULTISESSION capability and not CISCO variant anymore

Version 3.4.2
* Feature: add more information in crash report
* Fix: problem when trying to report exception errors
* Fix: better handling of on PIPE errors
    reported by: Thomas Raabo
* Fix: could not split MPLS routes
    reported by: Hideaki HAYASHI
* Fix: not correctly handling NOTIFICATION message
    reported by: Hideaki HAYASHI
* Fix: do not block on a peer should a socket become blocking
    reported by: Wouter Miltenburg
* Fix: API JSON message id incrementation
    reported by: Wouter Miltenburg

Version 3.4.1
* Fix: on bad JSON message
    patch from: Wouter Miltenburg
* Fix: parsing of default route
    reported by: Wouter Miltenburg
* Fix: remove legacy exabgp.tcp.timeout
* Fix: forgot some processes options when printing neighbor
* Fix: bad function call for API
* Fix: correct JSON for OPEN
* Fix: issues with bad naming of APIOption
    patch from: Wouter Miltenburg
* Fix: do not try to be clever (and possibly get it wrong) and rely on
  keepalive timer to detect TCP faults
* Fix: formating issue of extended community
* Fix: issue with EOR
* Fix: caching issue
    reported by: Wouter Miltenburg
* Fix: make sure we do not call select with a negative time
    reported by: Wouter Miltenburg, Daniel Piekacz
    patch from: Wouter Miltenburg
* Fix: handle AS4_PATH with PARTIAL bit set
    reported by: Daniel Piekacz
* Fix: bug with generic attribute generation
* Fix: bad Notification
    patch from: Wouter Miltenburg
* Fix: bad Keepalive JSON message
    patch from: Wouter Miltenburg

Version 3.4.0
* Feature: add support for extended-attribute for FlowSpec
* Feature: more detailed JSON objects
    patch from: Wouter Miltenburg
* Feature: support for L2VPN (experimental)
    patch from: Nikita V. Shirokov
* Improvement: better handling of NOTIFICATION received during OPEN
  negotiation
* Improvement: ExaBGP can restart failed helper process
* Fix: Do not reconnect too fast when connection fails
    reported by: Robert Barnes
* Fix: Invalid JSON object for route-refresh
    reported by: Robert Barnes
* Fix: We were not reporting the NLRI of the route received when
  exabgp.log.routes was set
* Fix: accept exabgp_tcp_port as configuration option and not only
  exabgp.tcp.port
* Fix: duplicate line output
* Fix: bad refactorisation which caused an bad ASN4 bug
* Fix: change EOR from IPv4 multicast (mistake) to IPv4 unicast
    reported by: Mark Treacy
* Fix: bad encoding of flow fragment encoding
    reported by: Andrei-Marius Radu
* Fix: bad reporting of process open sending
    reported by: Mark Treacy (with patch, thank you)
* Fix: Incorporating NETBSD compatibility patches
* Fix: Generation of Generic Attributes
* Fix: Faster reactor (should be able to process much more API/BGP messages)
* Change: new commands for the configuration of the API
* Change: JSON objects now include a unique neighbor identifier
* Change: JSON objects now include a counter for unique message id
* Change: JSON objects now include a "type" to now how to best parse them
* Change: JSON new EOR object
* Change: JSON new Flow format
* Change: slight variation with the command line option names, now using
  docopt patch from: Michael Robert Watson
* Change: the profile information is now exported in kcachegrind format
* Compatibility: JSON re-introduced the family under the "announce"
  section (removed by mistake)
* Compatibility: restoring integer as default time, high resolution must
  be enabled to not break older installations
* Change: JSON and Text shutdown object now shows the PID and PPID

(he)