Added new Printer Host mode Class driver.

Added new Printer Host mode ClassDriver demo.

Added table of supported classes and modes to the main USB Class Driver documentation.

LUFA/Drivers/USB/Class/Host/StillImage.h

@@ -72,7 +72,7 @@
 				struct
 				{
 					bool IsActive; /**< Indicates if the current interface instance is connected to an attached device, valid
-					                *   after \ref HID_Host_ConfigurePipes() is called and the Host state machine is in the
+					                *   after \ref SI_Host_ConfigurePipes() is called and the Host state machine is in the
 					                *   Configured state
 					                */