[AD] AL_RAND(), final round

[Angelo Mottola <a.mottola@xxxxxxxxxx>]

Here's a proposed new definition to be placed on the docs, so I can apply
the patch and we can close this topic.
It's a little modification of Peter's proposal:

<b>AL_RAND</b><br>
   On platforms that require it, this macro does a simple shift
   transformation of the libc rand() function, in order to improve
   the perceived randomness of the output series in the lower 16 bits.
   Where not required, it directly translates into a rand() call.

Please give me a "go" if it's ok.

On other news, the MacOS X port now features a working joystick driver,
which makes it feature complete :)

-- 
Angelo Mottola
a.mottola@xxxxxxxxxx