Reduce the number of Curses.refresh calls

fzf

@@ -638,7 +638,9 @@ class FZF
     Thread.new do
       begin
         while blk = @queue.shift
-          blk.call
+          blks = [blk]
+          blks << blk while blk = (@queue.shift(true) rescue nil)
+          blks.each { |blk| blk.call }
           refresh
         end
       rescue Exception => e