[IO] rework dprintf to take a debug level, defined in DEBUGLEVEL

printf at the moment just calls dprintf, but soon will become
a seperate I/O queue.
diff --git a/include/stdio.h b/include/stdio.h
new file mode 100644
index 0000000..ebabfca
--- /dev/null
+++ b/include/stdio.h
@@ -0,0 +1,12 @@
+#ifndef __STDIO_H
+#define __STDIO_H
+
+#include <debug.h>
+#include <printf.h>
+
+void putc(char c);
+int puts(const char *str);
+int getc(char *c); // XXX not really getc
+
+#endif
+