WIP: (PDB-663) Convert PuppetDB to Ezbake build system

This significant patch introduces Ezbake to PuppetDB, providing all the
required changes and some cleanups as well to make this possible:

* Of note, the old system is still around, until we work out how to do source
  based installations of PuppetDB in this new world. This will be done as
  another piece of work separately.
* CONTRIBUTING.md has been updated to the latest version from Puppet
* ERRATA.md has been removed, we have a ticket tracker
* Some changes we did on the old system:
 * Dependencies on latest Puppet & Facter have been changed in older system
 * Pathing updated to reflect closer to ezbake
* Debian 6 & Ubuntu 10.04 have been retired. We made this decision due to the
  reluctance to transfer the java lookup code in /etc/default/puppetdb into
  ezbake. Since this code is required to support Oracle JDK installation of
  Java 7, retirement was inevitable. Since these versions of the distros are
  nearly end of life anyway, we gave our users a stepping stone, by providing
  this in the first place, we feel this was an okay move.
* All beaker tests have been modified to work in an ezbake world.
* We've decided to use the nrepl trapperkeeper service now, to avoid conflicts
  and to finally shed that old code. We have updated the code and documentation
  to reflect this, and we provide a warning if users use the old [repl] block.
  Instead users must define the [nrepl] block, and it is no longer possible to
  choose a `type` of repl service.
* The package `puppetdb-terminus` is now called `puppetdb-terminii` and we've
  changed the references in code and docs to use this now. A module change will
  be required at some point, but this work is separate.
* Beaker tests are now in a script shipped with the project for Jenkins to use.
* Binaries are now installed in /usr/bin instead of /usr/sbin as per the ezbake
  standards.
* Lots of template files were transferred into resource/ext, this is what ezbake
  expects.
* Documentation has moved inside /usr/share/puppetdb/docs to a new location
  depending on the distribution. This is to follow the ezbake standards.
* project.clj was updated to make ezbake work, and to fix some warnings from lein
  deploy.
* A lot of softlinks were removed from /usr/share/puppetdb, that were pointing
  at the /var/lib/puppetdb & /etc/puppetdb/ spaces, I believe this was a partially
  completed migration from the past. The module for example had to be updated, so
  only the puppetdb module 4.1.0 will even work once we ship this.

Signed-off-by: Ken Barber <ken@bob.sh>
termini >= plugin in Puppet semantics. There are many different plugin types, termini implies its a plugin, the semantics isn't obvious but there is no reason to reiterate this everywhere: https://docs.puppetlabs.com/references/latest/indirection.html