By Eric Martyn and John Morris HALIFAX, Nova Scotia (Reuters) -Powerful storm Fiona slammed into eastern Canada on Saturday with hurricane-force winds, forcing evacuations, blowing over trees and powerlines, and reducing many homes to “just a pile of rubble.” The U.S. National Hurricane Center (NHC) said the center of the storm, downgraded to Post-Tropical Cyclone Fiona, was now in the Gulf of St. Lawrence after racing through Nova Scotia. After taking its toll on Nova Scotia and Prince Edward Island, the storm battered Newfoundland, but is now likely to weaken, the NHC said. Port aux Basques,…