feat(Request): Also accept query params from POSTed forms

Fixes #170
Wrap default responders with global hooks wrt #223

This enables global hooks for OPTIONS and Method Not Allowed (405)
default responses. This fixes issues with CORS preflight OPTIONS
requests not getting correct headers set by custom hooks.
Drop blank lines to fix flake8 complaints wrt #233
test(falcon-bench): Add tox environments to run falcon-bench wrt #222

Added tox environments to run falcon-bench on supported pythons.
fix(test) Install coveralls for travis runs
Merge pull request #238 from sebasmagri/global-hooks-for-default-responders

Wrap default responders with global hooks wrt #233
doc(AUTHORS): Add sebasmagri to AUTHORS. Thanks Sebastián!
test(testing.create_environ): Cover missed branches

This patch adds a couple tests to ensure that a couple code branches
in create_environ are exercised.
doc(tutorial): Fix markup around inline literal text
doc(tutorial): Link to PEP-3333
doc(tutorial): Added 3 more sections

This patch fills out the remaining major content sections in the
tutorial and fixes some typos and the like in the other sections. It also
adds a FAQ placeholder file and some notes for the advanced tips-n-tricks
placholder as they came to mind while working on the tutorial.
Merge pull request #240 from sebasmagri/falcon-bench-in-tox

test(falcon-bench): Add tox environments to run falcon-bench wrt #222
Merge pull request #243 from kgriffs/issues/112

doc(tutorial): Added 3 more sections
test(tox): Add cython envs to tox and travis

In order to catch any subtle cython errors, this patch ensures we are
gating on some cython envs.
test(pep8): Fix errors reported by latest flake8 version
test(bench): Fix py26 incompatibilities

This patch fixes some py26 incompatibilities in falcon-bench and passes
positional args through tox for py26_bench and friends, so benchmark
params can be tweeked as needed.
test(travis): Re-enabling pypy env for TravisCI

PyPy was previously removed due to a bug in Travis, but that has now
been resolved, so let's start gating on it again.
fix(API): Default on_options responder causes Cython type error

It was found that Cython's free function type is recognized as a function
by inspect.getargspec. Since the code that depended on that hasn't been
needed for a couple Falcon versions now (iirc), it was simply removed to
work around this Cython bug.

Triggered by Issue #233
fix: Remove ordered dict dependency for py2.6

This patch just uses a regular dict on py2.6 for creating error
response bodies. It simply isn't worth the extra dependency.

Closes Issue #226
test: Fix result decoding of error bodies

Some tests were failing under Py3K since the json library behaves a little
differently when it comes to decoding bytestrings. To fix this, the
simulate_request helper method was extended to take a new "decode" arg,
so tests can get a decoded string right off the bat.

Here is the docstring:

decode: If set to a character encoding, such as 'utf-8',
    the method will assume the response is a single
    byte string and will decode it and return a single
    wide string instead of the raw WSGI response iterable.