Frank Ocean is having a rough week. After cutting short his performance at Norway's Oya music festival last Thursday only four songs in - a spokesperson cited vocal problems - the R&B singer has now cancelled the remainder of his European concert tour, including a nine-city run opening for Coldplay. “Let me start by saying I feel like an asshole right now," said the R&B singer in a statement posted to the official Facebook page of Sweden's Way Out West festival, where he had been slated to perform. "But a tough decision had to be made in regard to my schedule...