Don't put trailing whitespace in JSON output.
Drop "..." when converting section titles to ids. This was the original intention of the code; it was a mistake that ellipses ever made it into section ids.
Make AbstractNum an actual object.
Move numbering methods to the Numbering object.
Cache result of Numbering.get_num_levels.
Compute AbstractNum.computed_labels eagerly when the Numbering object is created.
Cache Num.computed_levels.
Compute Num.computed_levels eagerly.
Simplify Num.computed_levels computation.
Remove offensive level_limit parameter from a Numbering method.
Simplify Document.get_list_style_at_level, since computed levels are now cached.
There are actually only 9 numbering levels in Word. Add some comments too.
Cope with w:lvlOverride>w:startOverride in certain situations, to eliminate bogus warnings so I can report the actual numbering glitches in the document. Ugh.