I'm looking at the calibre/gui2/convert/look_and_feel.py module, and it's got a bunch of operators in it whose provenance I can't determine:
Code:
TITLE = _('Look & Feel')
ICON = I('lookfeel.svg')
HELP = _('Control the look and feel of the output')
The "_" and "I" functions... what are those and where are they defined?