(dired-move-to-filename-regexp):

(dired-move-to-filename-regexp):
Do not distinguish between ASCII letters and non-ASCII characters.
Don't allow comma except in the form "month day, year".
Don't allow space between month name and comma.
Clean up the code that checks for trailing period, comma, and space.
Remove now-obsolete comments, and add more commentary about
Japanese dates.
Always gobble up trailing spaces, instead of doing it only sometimes.