Get Python 3 support to alpha status (unit tests run and pass)

[svanoort]

Requires python 3.3+ because of back-compatibility support there.

Many potential issues were fixed for 1.6 release (especially around modules and removed features) and tests will at least run mostly.

Here's what's left:

• Many ugly dependencies on unicode type (encoding/decoding to it aggressively, sigh). - solved
  • Mostly in parsing/config handling logic, so the refactoring in 1.7.x will reduce this. - it did
• mock.assert_any_call broken for some reason - *
• Subtle issues with use of map/lambda in the math sections of benchmark (Python 3 map function now returns an iterable, not a concrete list). - solved
• New - can't make the TestFailure objects resolve to false (functional test error)
  • Needs a unit test
• New - header parsing: 'str' does not support the buffer interface
  • Needs a unit test

[svanoort]

Completed by parsing refactors, culminating with ae0ef7f