Alternative random generator functions

[Divasson]

Thanks!

I should have started by there. And the names are easy to find, too: randpoisson, etc.

And in the "other" key of the help info related to the function, the other new random distributions appear too. (Note to Tim: the new random distributions do not appear in the "other" help menu of the "old" ones - that was why I could not find them at the beginning. They seem to be two separate sets, as seen from the help menu point of view)