Six install in the package dir is not necessary anymore

Scss module does not need to be imported to load the variables from scss.scss_meta
Adds requirement for enum34 if python version is < 3.4
Adds tox file
Win32 / Py3 compat
py26 compat
Merge pull request #302 from tkhyn/compat

Compatibilty (windows, python versions)
Merge compat changes