README: announce switch to no_mersenne.
README: mention mersenne branch with caveat
README: tweak mention of mersenne branch
treeprng.py: no_mersenne useage docstrings.
treeprng.py: more doc fixes
README chopped down.  treeprng.py mods started.
treeprng.py: copy whole self, not just hash
clear up README
no_mersenne treeprng.py working, README reflects
README: "Soon, no_mersenne should become MASTER."