cuekit and cuenorm: three subtitle formats, one cue stream

parity/cases/cuenorm/multiline.srt

@@ -0,0 +1,9 @@
+1
+00:00:01,000 --> 00:00:03,000
+The mill stood at the northern end,
+where the fall of the river was steepest
+and the ice came latest.
+
+2
+00:00:03,000 --> 00:00:05,000
+Its wheel was undershot.