[racket-dev] the new `racket/gui' --- now with bug reports

The new implementation of `racket/gui' is almost ready for everyday
use. I've switched to the new implementation for reading and writing
e-mail (i.e., this message was composed using the new implementation),
but I haven't yet switched for using DrRacket or for running Slideshow
in class.

I'm now happy to accept bug reports for the new implementation,
although there are known gaps and problems:

 * No platform-specific printing.

 * No GL support in canvases.

 * Cocoa: drawing to a bitmap is different than drawing to a canvas (so
   that pixels in a line or text can vary).

 * Gtk: no `register-collecting-blit'.

 * Gtk: more work is needed on canvas refresh to avoid flicker and to
   reflect the effect of one key/mouse event before handling another.

 * Gtk with some Unix variants: libraries like libjpeg and libpng are
   not located correctly.


The code is still hosted here:

   http://github.com/mflatt/gr2
 
Beware that I occasionally pull with `--rebase' from the main Racket
repository and push to gr2 with `--force'.