Revert "make passage headings bold." (they already were?)

This reverts commit 735ea98c0c48763d2330524cb0048e951fc908b6.
Remove stray \else{}
Import cross-references e.g. \csuse{xrefGenx1x1} for Gen 1:1
Ensure \thechapter is just numeric
Put cross-references in margin (doesn't fit yet though)