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
Fix bytestring in make_filename_hash (py3 compat)
Merge pull request #302 from tkhyn/compat

Compatibilty (windows, python versions)
Merge compat changes
Adds support for use-percentages
Merge 'use-percentages' support from branch 'import_sprite'