From The Boston Globe Thirty years after the fall of the Berlin Wall and the revolutions in Eastern Europe, a reporter who was on the ground weighs the fallout. Presidential candidate Vaclav Havel waves to his supporters from a balcony in Prague in December 1989.REUTERS On a chilly November evening in the fall of 1989, I stood on a busy street in Prague and wondered if spring would return. Twenty-one years earlier, in 1968, the “Prague Spring” had brought students and workers