Runes in Plan 9 were limited to the 16-bit BMP when I drew up
the RPC protocol between graphical programs and devdraw
a long time ago. Now that they can be 32-bit, use a 32-bit wire
encoding too. A new message number to avoid problems with
other clients (like 9fans.net/go).
Add keyboard shortcut alt : , for U+1F602, face with tears of joy,
to test that it all works.
Otherwise, the type of the expression will be int, and if written to
a uvlong (or just a ulong on most 64-bit systems), it will be
sign-extended.
This was going on in drawfcall with Mouse.msec, which is declared
as a ulong.
This fix assumes that the protocols only send unsigned numbers,
which is true.
