Add "How to Contribute" to docs
Integrate Contribute with Install
Merge pull request #391 from hoosteeno/master

Add "How to Contribute" to docs
[fix bug 842293] Allow filtering of incomplete profiles in Admin panel.
[fix bug 809481] Do not use hash when username is taken.
[fix bug 842292] INCOMPLETE

Don't index in ES incomplete profiles.
Don't list incomplete profiles in groups.
Don't show profile of incomplete profiles.