infuse some constness
touch up wEDFFileDetails
use agh::str::sasprintf instead of snprintf_buf, when passing filenames as %s, just in case
towards 0.9.2
correctly generalize drawn state of montage things on main SF menu

with some ICM
cplusplusify things
ensure all SF montage menu items are updated
use sasprintf where appropriate
move common code for hypnogram im/export from menu callbacks to hypnogram.cc