Merge pull request #585 from ankit-maverick/typos

Correcting typo in the reference section of adjust_sigmoid
fix blank print for python2
Merge pull request #586 from sciunto/print

MIN: use print() instead of print
cast range to list for python3
minor contrib.
MIN: remove unnecessary brackets
Merge pull request #588 from sciunto/range

FIX: cast range to list for python3 compatibility
Merge pull request #587 from sciunto/import

MIN: fix unused import
import configparser for python3
Merge pull request #589 from sciunto/configparser

import configparser for python3
fix path import viewers
fix import urllib2 for  python3
workaround for itervalues
fix iteritems for python3 compat
First quick implementation of BRIEF Feature descriptor
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