code simplification
Changing the way we pull location out so we can avoid the bug with cfg-config's parser
Reverting the 'fixes' I made to cfg-parser: they don't work.  But the prior commit should be fine: cfg-parser does provide reliable location information for tokens, and that's enough for ragg to do its work.
in the middle of writing helpers to read identifiers out of rules.
Added test for references to ids without definition