More work on the Mass Storage Host mode Class driver.

Added  ATTR_NON_NULL_PTR_ARG() attributes to the class drivers to improve user code reliability by disallowing explicit NULL pointers as pointer parameters in function calls where the parameter must not be NULL.

Disabled building of the Demos/Host/ClassDriver directory until Host Mode Class drivers are complete to prevent build errors in the meantime.

LUFA/ManPages/FutureChanges.txt

@@ -13,11 +13,16 @@
   *
   *  <b>Targeted for This Release:</b>
   *  - Finish Host Mode Class Drivers
+  *      ( ) Audio
+  *      (C) CDC
+  *      (S) HID
+  *      ( ) MIDI
+  *      (S) Mass Storage
+  *      ( ) Still Image
   *  - Add overviews of each of the officially supported boards to the manual
-  *  - Add hub support to match Atmel's stack
-  *  - Finish AVRISP Project
   *
   *  <b>Targeted for Future Releases:</b>
+  *  - Add hub support to match Atmel's stack
   *  - Add standardized descriptor names to device and host class driver structures
   *  - Remake AVRStudio project files
   *  - Add detailed overviews of how each demo works