units: Support start of line comments with '#'
	Modern GNU units(1) supports comments anywhere with '#' but take the easy route for now and at least support start of line # comments.
units(1): Convert units.lib to use '#' instead of '/'.
	This allows us to run GNU units against our data files and compare the output.
	In addition, current units(1) does not support '/' as a comment at all.
Make options KPI more generic to allow it to be used for ports too,
not only for LUNs.