Export will fail if backup is run while export, so be more flexible.

  Missing import

   As we don't read entire file, the regex can eventually get
   garbage on the latest line to parse. This commit make it tolerant
   while check.

This is required when the only criterion is on the command-line.
Since we have wrappers to work around the shebang limitation,
the --name option can't be used anymore for Python applications.

  Pin version of setuptools as >=34 don't work

resiliencetest: Verbose log between the interactions to know if the software is working for failing.

  It means there is no extra test to run.

  The full log is available on suite.log at the erp5testnode anyway.

  taskdistribution works on failover mode if master is undefined, so it is not needed to have 2 methods

  Consider the last start date to not include same entry multiple times

/reviewed-on !11

  In general, We can consider that at worst 1ms is added to
  ipv4 response, due the usage of openvpn.

  We can also consider that we accept a certain increase
  on latency for various reasons, if we are on a
  congested link. So we can consider that 10% is
  reseonable enough.

  The goal of this promise it to detect the real slowliness, rather
  them minor temporary failures, due internet oscilation.

  Add new promise to check re6st is on optimal status

  Added a promise to test if there is a packet lost when ping to an IPv4/IPv6.

  Added new promise to inspect an apache error log to detect failures if failures occurred.

@Tyagov 

Some screenshots:
![Screenshot_from_2017-03-24_11-54-11](/uploads/16f5901303b083dee2c771bcc77dd93b/Screenshot_from_2017-03-24_11-54-11.png)

/reviewed-on nexedi/slapos.toolbox!10