Minor patches:

- resend of the Config.in patch, updated to Kconfig,
   plus makes 'usbtest' modular when usb is;

- hmm, "usbfs" isn't locking here.  protect.  fix
   is basically from martin:  add/use a semaphore.

- that one-liner to make sure get_configuration is
   called correctly (with funkier test firmware).

- new 'realworld' module param can be used to turn
   off the real-world accomodations and be stricter
   about what device failures make ch9 tests fail.