[refactor] Split vendor.js away from application.js since the former is changed far less frequently (15m)
[skip] Removed date_format dependency in favor of D3's time.format (15m)
[refactor] Removed unnecessary gsub by specifying strftime format correctly (1m)
[skip] Displayed only unretired users in the tester bar (1m)
[refactor] Split vendor.css from application.css and continued slimming down the assets loaded for each dashboard (45m)
[fix] Correctly assigned a ticket created for a milestone to that milestone (20m)
[skip] Improved adding and removing tickets to/from milestones (10m)