PY3: test_url works in Python 3.3
use six.moves.urllib
Use ISO-8859-1 encoding for http basic auth. This fixes basic_auth_header for Python 3.x.
FIX basic_auth_header for binary input
COSMIT minor tweaks for w3lib.url + extra check for safe_url_string
FIX unicode handling in replace_escape_chars

b'binary text'.replace(unicode_arguments) was previously called
PY3 port w3lib.html to Python 3.

HtmlTests test case is split into more granular test cases and test methods;
some extra tests are added.
PY3 port w3lib.encoding to Python 3.3
MAINT switch to setuptools, add six to install_requires, add Python 3.3 to travis.yml
PY3 port w3lib.form to Python 3
TST fix travis build for Python 2.6
Merge pull request #13 from kmike/python3

[MRG] Python 3.3 support