Reduce progress bar polling (and make a constant)
Detect Emacs’s pseudo-TTY and don’t progress bar
Capitalize buildmessages
Print status messages even without progress bar

For example, in emacs shell, which is not a real TTY.
Fix “status message mode”

It has to wait for _pretty to become true so that it doesn’t start displaying statuses too soon.

There are now explicitly three modes, one where _progressBar is defined, one where it isn’t but _inStatusMessageMode is true, and one where neither is truthy.