Also: introducing eoRndGenerators.h for eoRndGenerator derived classes:
eoNormalGenerator
eoUniformGenerator
eoBooleanGenerator
eoNegExpGenerator
Note the suffix that are added to aid in determining what these classes do
Also added "using eo::rng" in eoRNG.h so nothing has to be modified.
We should gradually move to write eo::rng everywhere, and remove that using
directive to be almost full-proofed against possible name collision.