[Refugees and migrants arrive aboard the Tera Jet passenger ship at the port of Piraeus]ATHENS (Reuters) - Four out of five hotspots to register and process migrants and refugees in Greece are ready to receive people, the country's defence minister said on Tuesday. "It was a rather difficult operation," Greek Defence Minister Panos Kammenos, leader of the co-ruling, right-wing Independent Greeks party, told journalists. Greece, the main entry point into Europe for more than a million refugees and migrants since last year, has come under fire from the EU for failing to control the influx. ...