FirstFieldFocuser: synchronization

This simplifies the code and also prevents flaky failures of the test when the
console is open and focused.
UserData

Just a place to hold all the user-specific bits of data.
Housekeeping: inline bound closures
PaymentTracker: test: refactor to use auto-resolving deferred instead of setTimeout
FirstFieldFocuser: refactor to use less jQuery

The problem with jQuery is that it doesn’t fail when selector didn’t match
anything.
FormValidationResetter: refactor to use less jQuery

The problem with jQuery is that it doesn’t fail when selector didn’t match
anything.