The two test cases test, respectively, (1) context precedence and
(2) that section output not be rendered.  The two test cases were
originally proposed for inclusion in the Mustache spec test cases
in mustache/spec issues #31 and #32:

* https://github.com/mustache/spec/pull/31
* https://github.com/mustache/spec/pull/32

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)