Revert "correcting things"

This reverts commit afcc3cf519f254bd35adc57281466d731f092681.
adding a check of nil value in finger table
too much printf for 160 bits
refactoring test : separate 160 bits tests of 3bits tests
the minimal distance in findClosestNode is the distance if we get the successor
replacing finger[0] by successor
use pointer every where !
refactoring of addToRing
correct initialization of a newNode
changes on pretty printing
adding a func to init fingers table
lookup use use findClosestNode (finger table optimization)
better find closest node func : more controls to avoid infinit loop