use Google's CDN for jquery in testloading page
allow jsnumbers fromString() to parse most native racket numbers. (Thanks to DanKing for support)
throw runtime errors for known-bad numbers, such as #i#e5
improvements to number-parsing errors
add updated teachpacks that offer better error reporting, and image-as-TITLE functionality
Don't use hard-coded path to raco & racket. Save pid.

To make it easier to use local racket installations and monit, save
the pid to the /tmp directory.