Fix bug 1071230: Update "let us know" link
Bug 1024507: Measure use of Twitter and Facebook

Luke organized the logic so that Google Analytics event calls would work
correctly [1]. His commit was squashed into the prior commit to maintain
a history of working commits.

[1] https://github.com/groovecoder/kuma/commit/4bbd5f89e3539faeecdcbdb850c45508e265b709
fix bug 1070942 - add a contribute.json file
Merge pull request #2734 from openjck/1024507-twitter-facebook-research

Bug 1024507: Measure use of Twitter and Facebook
Merge pull request #2761 from openjck/1071230-let-us-know-link

Fix bug 1071230: Update "let us know" link
Merge pull request #2759 from jezdez/bug1070942-contribute.json

fix bug 1070942 - add a contribute.json file