add ability to render_tex to omit success messages
automatically also create preliminary PDF versions when generating results
hand one_time and quiet down, actually.
don’t print name if only evaluating a single course

progress reports for single evaluations will be handled differently from now on
be less verbose about already existing files
improve speed and progress display for single report creation

The speed improvement is achieved by not starting rake through
a shell again for each course. Rake takes very long to load because
all database connections need to be established and all Rails
libraries loaded.

Also display the common progress status. It counts the persons
(i.e. tutors and profs) needing evaluation instead of the course,
so it’s not skewed for large lectures.
style fix
fix questionnaire display
print course name
add time estimate to print_progress