[racket-dev] input methods under Unix/X

I've finally enabled input-method support in `racket/gui' under X.
(Input methods have long been supported for Windows and Mac OS X.)

One consequence of this change is that, under X,

 Shift-Ctl-U 3 B B Return

probably inserts `λ' anywhere that you can type in a Racket GUI
program, since Shift-Ctl-U triggers a mode in the default(?) Gtk input
method to type Unicode characters by their hexadecimal code points.
More usefully to many, CJK input should now work under Gtk.

Key-event handling is complex, and there are lots of ways that this
change could go wrong. Keep an eye out for new event-handling problems
under X.