Move all include files to src/include

- 86Box's own headers go to /86box
- munt's public interface goes to /mt32emu
- all slirp headers go to /slirp (might want to consider using only its public inteface)
- single file headers from other projects go in include root

src/include/86box/ibm_5161.h

@@ -0,0 +1,15 @@
+/*
+ * 86Box	A hypervisor and IBM PC system emulator that specializes in
+ *		running old operating systems and software designed for IBM
+ *		PC systems and compatibles from 1981 through fairly recent
+ *		system designs based on the PCI bus.
+ *
+ *		Emulation of the IBM Expansion Unit (5161).
+ *
+ *
+ *
+ * Author:	Miran Grca, <mgrca8@gmail.com>
+ *		Copyright 2016-2018 Miran Grca.
+ */
+
+extern const device_t ibm_5161_device;