Grokking ranges: some new algorithms and ranges

[bearophile]

Philippe Sigaud:

Hello, it seems you have re-done with ranges for D2 a good amount of things I did for D1:
http://www.fantascienza.net/leonardo/so/libs_d.zip

- bimap/nmap/map: having a single map able to do all that is better. The same for filters.
- setComprehension: better to have a set(range).
- comprehension: see select() in my dlibs.

Bye,
bearophile