Merge pull request #1 from mvexel/master

my edit suggestions
Proposed changes for #2
Adding @mvexel to the contributors
Added one other thing about listening to other points of view
Merge pull request #3 from osmlab/respectful-disagreement

Proposed changes for #2 - respectful disagreement
Update code_of_conduct.md

typo
Merge pull request #4 from jaakla/patch-1

Typo fix
add harassment definitions, adapted from http://geekfeminism.org/about/code-of-conduct/
add harassment definition