Switch to time-based progress reports
Switch to time-based progress reports

These are more consistent, so lead to a better UX.

I'm going to extract this out to another class though, as these instance
variables don't really have any place in the scanner.

mtimkovich/command-t,wincent/command-t,wincent/command-t,wincent/command-t,yrro/command-t,yrro/command-t,mtimkovich/command-t