first usable version of kernel and commands

After an year of hard work, this is a first "usable" version of Jehanne.

sys/include/usb/silabs.h

@@ -0,0 +1,12 @@
+/*
+ * This file is part of the UCB release of Plan 9. It is subject to the license
+ * terms in the LICENSE file found in the top-level directory of this
+ * distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
+ * part of the UCB release of Plan 9, including this file, may be copied,
+ * modified, propagated, or distributed except according to the terms contained
+ * in the LICENSE file.
+ */
+
+extern Serialops slops;
+
+int slmatch(char *info);