Improved badges
Updated contribution guide
Merge pull request #4334 from GrahamCampbell/4.1-badges

[4.1] Improved Badges
Merge pull request #4367 from GrahamCampbell/4.1-contr

Updated Contribution Guide
Merge branch '4.1'
Upgrade stability on 4.2 branch.
This doesn't need to change.
Update change log.