 - Makefile should know real dependencies
 - should record errors, particularly when parsing
 - handle repeated IEs
 - q_assign should remove old value (i.e. zero destination)
 - bit numbering is wrong; should be <size@high>
 - rename "item" to "field"
 - should be library (well, need at least more flexible name selection)
 - '#' comment character is dangerous; should use ';'
 - copies of adjacent fields should be merged
 - copies of partial bytes should be byte-wide if rest is only zeroes
 - should be able to have multiple selectors in one byte
 - should allow multiple values for case/multi labels
 - case/default needs better compile-time check
 - check for name collisions (currently handed to cc)
 - optimize
 - code needs a lot of cleaning
