This file is for ideas that have or have not yet been tried, and the
results of these ideas.

- If the email parser was able to emit warnings about misformed MIME
  that it encountered, we could turn this warnings into tokens.

- The numeric entity support looks like it will only support 8-bit
  characters - an obvious problem is from wacky wide-char entities.

  [tim] It replaces those with a question mark, because chr(n) raises
  an exception for n > 255, and the "except" clause returns '?' then.
  Is that a problem?  Probably not, for Americans and Europeans.

- The ratio of upper-case to lower-case characters in an entire message.
  (I'm not sure how expensive it would be to calculate this).  A lot
  of the Nigerian scam spams I get are predominately upper-case, and
  none of my ham.

- A token indicating the length of a message (rounded to an appropriate
  level.  Also a token indicating the ratio of message length to the
  number of tokens, and a token indicating the number of tokens.
