This commit merges pvande's spec-compliant branch `e06bed51`
into the development branch with all tests (including v1.0.3 spec tests) passing.
Also, speed did not slow considerably.  Further refactoring and clean-up are
still needed.

Here are results of the benchmark script before and after (using
`python tests/benchmark.py 10000`):

development (before):

    Benchmarking: 10000x

    0.931457042694
    3.08717703819

development (after):

    Benchmarking: 10000x

    1.56453585625
    4.69798803329

And here were the test results before the commit (now all 280 are passing):

(using `nosetests --with-doctest --doctest-extension=rst -i spec`)

    Ran 280 tests in 0.535s

    FAILED (errors=5, failures=39)