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.

Silence a few more warnings. Strip down the mkfiles more. Fix bug in X11 mouse handling, note groups.