fix path import viewers
fix import urllib2 for  python3
workaround for itervalues
fix iteritems for python3 compat
Refactor contribution workflow
Change branch name for consistency across guidelines
Fix typo
Add additional advice about rebasing
Use long parameter version --force rather than -f
Tweak Sphinx rendering of contribution page
Merge pull request #4 from tonysyu/rebase-workflow-edits

Tweak Sphinx rendering of contribution page
use items/values for python2/3 compat
Merge pull request #593 from ahojnnes/rebase-workflow

Rebase workflow
Merge pull request #590 from sciunto/python3fix

few Python3 fixes