Fixed all Class drivers to ensure they have appropriate guards on each function to ensure the device is enumerated before running, fixed error codes on all guards to return "DeviceDisconnected" where possble.
Renamed HOST_SENDCONTROL_DeviceDisconnect enum value to HOST_SENDCONTROL_DeviceDisconnected to be in line with the rest of the library enum error codes.
Descriptor processing routines now pass around void pointers rather than uint8_t pointers, as their destination datatype is know well known -- they are just streams of bytes until they are cast to the correct destination type by DESCRIPTOR_CAST.