traviiiiiiiiis

A test was counting on a cache being written to, but it wasn't because
the storage got an invalidation later than expected (on suitably slow
machines, like travis and an AWS dev machine of mine).

that was making a test failure hard to interpret.

Load uses load before

  with regard to the load lock.  This allowes ZEO to work with the
  upcoming ZODB 5, which used loadbefore rather than load.

  Reimplemented load using loadBefore, this testing loadBefore
  extensively via existing tests.

Drop support for Python 2.6 and 3.2.

- 2.6 is long out-of-maintenance, and a security quagmire.

- 3.2 cannot be tested on Travis.

Add support for PyPy.

Let checkQuickVerificationWith2Clients use a longer timeaut and raise an assertion error if the timeout fails. Trying to debug intermittant failures on Travis, seen in all versions of Python.

Per @mgedmin, use a renormalizing pattern to fix the unicode string matchin in Python3. Also just print the data for the storage we expect, because the missing u prefixes change the spacing when pprint nests dicts and things don't match under Python2.

Fix the ruok protocol under Python3: a bytes/unicode problem. However, the doctest cases still don't pass because they have leading u prefixes in them.

One more place to account for the socket.error switchero on Python3. Still doesn't fix nagios/ruok though.

Make the nagios metrics come back in a deterministic order. This fixes the nagios test under PyPy, but they still fail under Python 3 for the same reason test_ruok does.

test_ruok was hanging under Python3. Now it doesn't hang but just fails with 'struct.error: unpack requires a bytes object of length 4'

Fix some test failures under Python3.3+. This loop can also raise a RuntimeError([Errno 9] Bad file descriptor), though, so not all are fixed. But this may be enough to fix the hang.

Try to remove use of virtualenv in .travis.yml; all the travis builds were running under Python 2.7.3 because of it.

Make the virtualenv python report its version; seeing /usr/lib/python2.7 in the python2.6 traceback paths is making me nervous.