isolation in CMSSW

generic isolation in the reference manual

annunciato cosi':

according to a discussion had with all the people who are contributing
with isolation tools development, I made the following rearrangement of
Francesco Fabozzi's Generic Isolation module:

* the isolation algorithm(s) with no dependency
on Framework are in the new package:

PhysicsTools/IsolationUtils

* the isolation generic producer module(s)
goes in the new package:

PhysicsTools/IsolationAlgos

In this way, it will be possible to add Reflex dictionaries to
algorithms in PhysicsTools/IsolationUtils for FWLite use of isolation.

The old package PhysicsTools/LeptonIsolation will be removed in next
releases (nightly + next 1.5.0).