[ClusterLabs] sbd v1.3.1

[Klaus Wenninger]

Hi sbd - developers & users!

Thanks to everybody for contributing to tests and
further development.

I tried to quickly summarize the changes in the
repo since it was labeled v1.3.0:

- Add commands to test/query watchdogs
- Allow 2-node-operation with a single shared-disk
- Overhaul of the command-line options & config-file
- Proper handling of off instead of reboot
- Refactored disk-servant for more robust communication
  with parent
- Fix config for Debian + configurable location of config
- Fixes in sbd.sh - multiple SBD devices and others

Since we don't have a clear versioning-strategy (maybe
I just don't know where to search for) I used v1.3.1 for a
new label - although stuff behind some of the bullet-items
from above might be called feature and thus might have
legitimated a bump to v1.4.0 according to rules used
elsewhere.

One point I didn't mention in the label-description -
because it actually doesn't directly influence the
content of the package once built for a distribution -
is that we have travis-CI now.
I've added builds against CENTOS-6 & CENTOS-7 +
tests running on both of them. (Everything in docker-
containers btw. - privileged for the tests as the
test-script needs to setup device-mapper)
At the moment we are running the test-script more or
less as provided by l-mb in the good old days.
So please feel invited to add additional tests,
improve the existing ones and add builds/tests against
other distributions.

And last but not least I don't want to leave
 
PR#27: cluster-servant: only report online if quorate
       or never had quorum

unmentioned.
It is definitely interesting and picks up a topic
that has been on the todo-list for a long time -
periodic alive checking with corosync - as kind
of a side-effect.
Unfortunately the patch doesn't apply anymore both
syntactically and semantically since I've merged
the long time outstanding PR for 2-node-awareness.
I'm sorry for that and I promise to have a look
during the next days. Maybe it is really time for
a v1.4.0 when that is merged.

Regards,
Klaus