Fix the "transition_to_primary" upgrade.

fixes #3551
Add Selenium and Frontend tests for #3551
Simplify and clarify the Selenium and front end tests.

* To Selenium, simplify the tests.
* To Selenium, add better commenting.
* To Frontend tests, clarify the transition_to_secondary test names to be self explanatory.
Update package.json metadata, fixes #3555
We're actually on b2, not b1.
Add bugs to package.json as well. Because why not
Use bugs literal, reduce net lines of code by 2.
Merge pull request #3556 from mozilla/packagejson

Update package.json metadata, fixes #3555
Merge pull request #3552 from mozilla/issue_3551-transition_to_secondary

Issue 3551 transition to secondary
document changes in train-2013.06.19
bump version in dev after branching train-2013.06.19