Fix errors in the SingleUSBModeTest build test. Fix logic errors in USBMode.h.

BuildTests/SingleUSBModeTest/Dummy.S

@@ -34,7 +34,8 @@
 # Mandatory entry point for successful compilation and link
 .global main
 main:
-
+	# Force code generation of the base USB stack
+	call USB_Init
 	
 # Mandatory callback needed for base compile of the USB driver
 .global CALLBACK_USB_GetDescriptor

BuildTests/SingleUSBModeTest/makefile

@@ -25,13 +25,13 @@ end:
 	@echo
 
 compile:
-	$(MAKE) -s -f makefile.test clean elf ARCH=AVR8 MCU=at90usb1287 CCFLAGS='-D USB_DEVICE_ONLY'
-	$(MAKE) -s -f makefile.test clean elf ARCH=AVR8 MCU=at90usb1287 CCFLAGS='-D USB_HOST_ONLY'
+	$(MAKE) -s -f makefile.test clean elf ARCH=AVR8 MCU=at90usb1287 CC_FLAGS='-D USB_DEVICE_ONLY'
+	$(MAKE) -s -f makefile.test clean elf ARCH=AVR8 MCU=at90usb1287 CC_FLAGS='-D USB_HOST_ONLY'
 
-	$(MAKE) -s -f makefile.test clean elf ARCH=XMEGA MCU=atxmega128a1u CCFLAGS='-D USB_DEVICE_ONLY'
+	$(MAKE) -s -f makefile.test clean elf ARCH=XMEGA MCU=atxmega128a1u CC_FLAGS='-D USB_DEVICE_ONLY'
 	
-	$(MAKE) -s -f makefile.test clean elf ARCH=UC3 MCU=uc3a0256 CCFLAGS='-D USB_DEVICE_ONLY'
-	$(MAKE) -s -f makefile.test clean elf ARCH=UC3 MCU=uc3a0256 CCFLAGS='-D USB_HOST_ONLY'
+	$(MAKE) -s -f makefile.test clean elf ARCH=UC3 MCU=uc3a0256 CC_FLAGS='-D USB_DEVICE_ONLY'
+	$(MAKE) -s -f makefile.test clean elf ARCH=UC3 MCU=uc3a0256 CC_FLAGS='-D USB_HOST_ONLY'
 
 clean:
 	$(MAKE) -s -f makefile.test clean ARCH=AVR8 MCU=at90usb1287

LUFA/Drivers/USB/Core/USBMode.h

@@ -239,13 +239,15 @@
 				#define USB_CAN_BE_DEVICE
 			#endif
 
-			#if   ( defined(USB_CAN_BE_DEVICE) &&  defined(USB_CAN_BE_HOST))
-				#define USB_CAN_BE_BOTH
-			#elif ( defined(USB_CAN_BE_DEVICE) && !defined(USB_CAN_BE_HOST))
+			#if ( defined(USB_CAN_BE_DEVICE) && !defined(USB_CAN_BE_HOST))
+				#if !defined(USB_DEVICE_ONLY)
 					#define USB_DEVICE_ONLY
+				#endif
 			#elif (!defined(USB_CAN_BE_DEVICE) &&  defined(USB_CAN_BE_HOST))
+				#if !defined(USB_HOST_ONLY)
 					#define USB_HOST_ONLY
 				#endif
+			#endif
 
 			#if defined(USB_HOST_ONLY)
 				#if !defined(USB_CAN_BE_HOST)