random number generators for calc

[tino]

> > Small problems:
> >  - compiler warnings from within boost
> 
> We need to patch them out otherwise the Werror build will fail. It
> seems that these warnings are also fixed upstream.

This really confuses me. The warnings I'm getting are of the form

 ...boost/random/binomial_distribution.hpp:47:5: warning:
 declaration of 'p' shadows a member of 'this' [-Wshadow]

I'm also getting similar warnings even with boost 1.52, however only
if boost resides in a non-standard directory. Linking boost to

 /usr/local/include

and using -I/usr/local/include makes all the -Wshadow warnings
disappear.

Don't know if you can confirm this but this is beyond me:

# ln -s .../core/solver/unxlngx6.pro/inc/external/boost /usr/local/include
# ln -s .../core/solver/unxlngx6.pro/inc/external/boost /tmp/include

$ cd .../core/sc/source/core/tool
$ g++ -Wall -Wshadow -c random.cxx -I/tmp/include
... [warnings] ...

$ g++ -Wall -Wshadow -c random.cxx -I/usr/local/include
[no warning]

> Just a few more comments about the patch. We need to ifdef all unused
> methods in random.[ch]xx otherwise they will be removed in nearly no
> time. We are removing unused functions to clean the codebase. Please
> also don't leave old code commented, we have git for code history so
> we don't need to keep all code as comments. Before I'll push the
> change with these modifications I'll check with a big file containing
> a lot of RANDOM functions to check that we are not introducing a
> performance regression.

Yes, thanks, that makes sense.
I hope it speeds up slightly...