Initial commit: Schunix as it stands before the SchOS rename

An x86-64 operating system built from xv6, now largely rewritten: SMP,
a copy-on-write root filesystem (SchFS), PCI/USB/virtio drivers, a TTF
rasteriser, and a Linux-numbered syscall ABI.

No history before this point -- the tree was never under version control.
This commit exists so the rename that follows has something to undo to.

include/date.h

@@ -0,0 +1,15 @@
+#pragma once
+
+struct rtcdate {
+  uint second;
+  uint minute;
+  uint hour;
+  uint day;
+  uint month;
+  uint year;
+};
+
+struct timeval {
+  long tv_sec;
+  long tv_usec;
+};