[Gm2] ISO RandomNumber module added

[Gaius Mulley]

Hi,

I've just added a module to the ISO library:  RandomNumber
which provides a few procedures for obtaining random numbers on
some basic data types.  Also fixed a bug in the PIM Random
module:

   * gm2/gm2-libs-pim/Random.def:  fixed declaration of
     RandomBytes to use VAR parameter.
     * gm2/gm2-libs-pim/Random.mod:  fixed declaration of
     RandomBytes to use VAR parameter.  Also improved
     implementation of RandomReal and RandomLongReal.
     * gm2/gm2-libs-iso/RandomNumber.def:  (New module).
     * gm2/gm2-libs-iso/RandomNumber.mod:  (New module).
     * gm2/Make-lang.in:  add RandomNumber.mod to the list
     of ISO modules.

I've updated the 4.1.2 tree and also the online documentation
to reflect these changes.

regards,
Gaius