2016-01-14 swift nsurlsession 遷移 同期 http://stackoverflow.com/questions/32950874/wait-for-download-task-to-finish-in-nsurlsession http://qiita.com/yonell/items/c5432207868fa2d5cfc9 http://qiita.com/akitaika_/items/2f4fca20a82cb6895329 http://swift-studying.com/blog/swift/?p=492 http://qiita.com/himara2/items/165393baac0bd1705bfe