emit scan codes for windows keys.

Reference: /n/atom/patch/applied/usbwinkey
Date: Sat Mar 22 21:26:37 CET 2014
Signed-off-by: quanstro@quanstro.net

--- /sys/src/cmd/usb/kb/kb.c	Sat Mar 22 21:26:15 2014
+++ /sys/src/cmd/usb/kb/kb.c	Sat Mar 22 21:26:16 2014
@@ -593,11 +593,14 @@
 	int i, j;
 	Scan uk;
 
+	/* should be in terms of usb code not scan code */
 	putmod(f, buf[0], obuf[0], Mctrl, SCctrl);
 	putmod(f, buf[0], obuf[0], (1<<Mlshift), SClshift);
 	putmod(f, buf[0], obuf[0], (1<<Mrshift), SCrshift);
 	putmod(f, buf[0], obuf[0], Mcompose, SCcompose);
 	putmod(f, buf[0], obuf[0], Maltgr, 1<<8 | SCcompose);	/* i don't understand this one */
+	putmod(f, buf[0], obuf[0], 1<<Mlgui, SClgui);		/* aka windows key */
+	putmod(f, buf[0], obuf[0], 1<<Mrgui, SCrgui);
 
 	/* Report key downs */
 	for(i = 2; i < n; i++){
--- /sys/src/cmd/usb/kb/hid.h	Sat Mar 22 21:26:17 2014
+++ /sys/src/cmd/usb/kb/hid.h	Sat Mar 22 21:26:18 2014
@@ -77,6 +77,9 @@
 	SCrshift	= 0x36,
 	SCctrl		= 0x1d,
 	SCcompose	= 0x38,
+	SClgui		= SCesc1<<8 | 0x5b,
+	SCrgui		= SCesc1<<8 | 0x5c,
+
 	Keyup		= 0x80,		/* flag bit */
 	Keymask		= 0x7f,		/* regular scan code bits */
 };