[CM] clm-random error and "double-float"

[Rick Taube]

sorry, too late! i took the renaming opportunity to add a new feature  
to weighting patterns suggested by a student of mine: if you  
specify :adjustable <number> then each time items are selected they  
become less/more likely by the :adjustable amount.

> Might it be best to rename them with something that prepends 'rand'  
> onto a name so that there is some pnemonic indication that they are  
> random?
>
> Just an idea,
>
> Cris