Add host mode USB Class driver stubs, add beginnings of a CDC host class driver.

Split out common defines/types from class drivers into a seperate common class driver directory.

Make central USB Class driver dispatch headers, used for both device and host modes.

LUFA/Drivers/USB/Class/StillImage.h

@@ -0,0 +1,57 @@
+/*
+             LUFA Library
+     Copyright (C) Dean Camera, 2009.
+              
+  dean [at] fourwalledcubicle [dot] com
+      www.fourwalledcubicle.com
+*/
+
+/*
+  Copyright 2009  Dean Camera (dean [at] fourwalledcubicle [dot] com)
+
+  Permission to use, copy, modify, and distribute this software
+  and its documentation for any purpose and without fee is hereby
+  granted, provided that the above copyright notice appear in all
+  copies and that both that the copyright notice and this
+  permission notice and warranty disclaimer appear in supporting
+  documentation, and that the name of the author not be used in
+  advertising or publicity pertaining to distribution of the
+  software without specific, written prior permission.
+
+  The author disclaim all warranties with regard to this
+  software, including all implied warranties of merchantability
+  and fitness.  In no event shall the author be liable for any
+  special, indirect or consequential damages or any damages
+  whatsoever resulting from loss of use, data or profits, whether
+  in an action of contract, negligence or other tortious action,
+  arising out of or in connection with the use or performance of
+  this software.
+*/
+
+/** \ingroup Group_USBClassDrivers
+ *  @defgroup Group_USBClassSI Still Image Device Class Driver - LUFA/Drivers/Class/StillImage.h
+ *
+ *  \section Sec_Dependencies Module Source Dependencies
+ *  The following files must be built with any user project that uses this module:
+ *    - LUFA/Drivers/USB/Class/Host/StillImage.c
+ *
+ *  \section Module Description
+ *  Functions, macros, variables, enums and types related to the management of USB Still Image Class interfaces
+ *  within a USB device.
+ *
+ *  @{
+ */
+
+#ifndef _SI_CLASS_H_
+#define _SI_CLASS_H_
+
+	/* Includes: */
+		#include "../HighLevel/USBMode.h"
+		
+		#if defined(USB_CAN_BE_HOST)
+			#include "Host/StillImage.h"
+		#endif
+		
+#endif
+
+/** @} */