util: add test for util.driver and improve reproduceTypedValue()

reproduceTypedValue() will now try hard to find numbers if it's a list of numbers

also rename test/overlay.py to fit the module name and our *test.py pattern
gui: allow free entry of values in combox boxes

can now enter any resolution/repetition that we want, and not just the possible ones

still ugly graphics
gui: add more predefined resolutions

Try to go at least down to the current value
gui: improve display of settings

don't use prefix for a given set of units
show more available binnings
support spectrometer binning (only first dimension should change)
update StaticText value
gui: fix scale computing from ROI

was using wrong formula for scale

also avoid recomputing the acquisition time too often and put it in a call after which tends to ensure repetition is updated before it runs