Non interference enforcement

[Remi Forax]

We currently ask users to write lambdas that doesn't interfere with the 
source collection
of a stream but it's not enforced in the code.

By example,
   list.stream().forEach(e -> { list.remove(e); });
may works or not depending how the pipeline is implemented.

This is a serous departure for the current way java.util collections works
and I wonder if we should not keep the fail-fast guarantee for those 
collections.

Rémi