[qhanzi] Updated error messages and improved accuracy

[Ben Bullock]

(I'm reverting back to sending to this list rather than using the news.sljfaq.org site.)

qhanzi.com is updated with some slightly improved error messages. Please see the attached illustrations. The error handling is done extremely conservatively, so that I have almost no legitimate Chinese character inputs which trigger the "too long" message, and similarly almost no legitimate inputs which trigger the "too many crossing lines" error, except for people who drew a character in an extremely odd way.

The accuracy is also slightly improved from before due to incremental improvements in the algorithm.