Splitting out UEFI bootloader code from kernel

Now the bootloader should be responsible for all initial setup,
loading the kernel, and then handing off to the kernel with
proper data in place.

src/boot/console.h

@@ -0,0 +1,7 @@
+#pragma once
+#include <efi.h>
+
+EFI_STATUS con_initialize (const CHAR16 *version);
+void con_status_begin (const CHAR16 *message);
+void con_status_ok ();
+void con_status_fail (const CHAR16 *error);