Update browser_helper.rb and warn for old Firefox and Safari
Use 'browser' gem for detection instead of custom regex
Update activity-monitor to use gem 'browser' instead of 'user_agent_parser'
Fix activity-monitor and lib/cdo extension
Better RBENV instructions

things kind of working, with hackery

clean things up a little
more cleanup
Add free play links to header
Tweak icon metrics
Checkpoint
Free play links for student dashboard
code review
Code review feedback
consolidate steps
Add hand cursor again to video play button.
Changed sharing URL.
Merge branch 'staging' into test
Fix padding on employee engagement landing page.
Merge branch 'staging' of github.com:code-dot-org/code-dot-org into staging
Hotfix: Fixed broken How To page.
Merge branch 'test' into staging