replaced dispatch_block_t with Swift closure type
replaced dispatch_block_t with Swift closure type

morizotter/BrightFutures,tranhieutt/BrightFutures,zhaar/BrightFutures,MattesGroeger/BrightFutures,Thomvis/BrightFutures,hoanganh6491/BrightFutures,Noobish1/BrightFutures,tranhieutt/BrightFutures,MattesGroeger/BrightFutures,hoanganh6491/BrightFutures,zenkimoto/BrightFutures,Noobish1/BrightFutures,morizotter/BrightFutures,Thomvis/BrightFutures,zenkimoto/BrightFutures,zhaar/BrightFutures