extract_wiktionary isn't being used yet, but describe it a bit
Slightly update English Wiktionary reader

... and delete the Japanese reader for now. Both Wiktionary readers
should be replaced with a new thing that uses extract_wiktionary once
it's ready.
slightly update wiktionary_en; new name for conceptnet5.stem

wiktionary_en.py has been ported to use the new organization of the
package. However, it has not been cleaned up or documented, because we
plan to replace it entirely.

'conceptnet5.stemmers' has been renamed to 'conceptnet5.stem', so it's
talking about the operation and not about whatever objects or functions
might perform it.
straightforward update of ptt_petgame reader