Watch out for overrun reading backwards integer
Only look for trailing data in text records
Check for mismatched lengths
Start recording image data
Be less strict about needing EXTH
Only look for 3 trailing data bits
Add test books with multiple images
Canonicalize logging
Add baretest target
Insert images
Start inserting xrefs

Not currently in quite the right place -- the added
anchors appear inside tags often.
Try not to insert anchor in tag

Still want to fix the offset calculations to be
accurate, but as a fallback try to avoid inserting
a tag inside another tag.

Manually hunting tag delimiters is brittle, but
better than nothing.