[CODE] Finalized ioctl and stevea

RESULTS:
	- stevea works properly but poorly documented and written;
	- ioctl is well documented and well written, but the registration
	  of the device in __init uses a old fashioned way that oblige
	  the user to chmod 755 /dev/my_device or write a udev rule

CONCLUSION (future points):
	- a final_kernel version merging the two:
		* start from ioctl and modify the __init as in stevea
		* send structs



Signed-off-by: Francesco Robino <frobino@kth.se>