Msgpack

AttributeError 'server' when StorageServer creation fails

Thanks!

Please travis!

Conflicts:
	CHANGES.rst
	setup.py

Fixed: ZEO needed changes to work with recent transaction changes.

Conflicts:
	CHANGES.rst
	setup.py

  transaction until we can sort out some recent breakage.

- Need to handle exception instances embedded within others.

  I dealt with this in msgpack using a "default" option (essentially a
  msgpack/json form of reduce).

  For pickle, we're still creating instance pickles in this case. :/

- Use a python-msgpack option to produce tuples rather than
  lists.  The ZEO protocol uses tuples far more often than lists.

  This really mostly or entirely affects tests.

  Removed workarounds for some test code that expected tuples and
  added some for test code that expects lists. :)

Avoid waiting on futures using timeouts -> major performance win on Python 2

When data are loaded, we notify waiting code before updating the cache.

This can confuse white-box tests that make assertions about the client
cache after a load, because the cache change may or may not have been
made yet.

By making an unimportant assertion less restrictive.

On Python 2, waiting on a future result with a timeout is very
expensive. (Because conditions with timeouts are very expensive.)

The thing is, we still want to use timeouts when we're disconnected.
We don't want requests to fail right away of the disconnection is
short.

We do a bit of a dance to only use a timeout if we're disconnected.

The ad-hoc server no longer leaves a configuration file behind.

Exit with failure codes instead of success codes on unsupported Python versions.