This drops the option to read tags from a disk file. I don't think I've
ever used this, and it requires quite a bit of circuitry to implement.
Also dropped -s/--string, because most tags can't be represented as
strings?
And tweaked -x/--hex flags to correctly parse spaces in arguments, so
now these are equivalent:
- ./scripts/dbgtag.py -x 00 03 00 08
- ./scripts/dbgtag.py -x "00 03 00 08"