Add upload/download of sud.json over the Sud websocket channel

Sud.download() returns the on-disk document; Sud.upload() validates,
persists, and resets the schedule, refusing mid-brew or malformed input
so the current schedule is never left half-applied.

tasks/sud.py

@@ -69,6 +69,11 @@ class SudTask(ATask):
 				self.sud.start()
 			elif 'Confirm' in pair[0]:
 				self.sud.confirm()
+			elif 'Download' in pair[0]:
+				await self.send({'Json': self.sud.download()})
+			elif 'Upload' in pair[0]:
+				if self.sud.upload(pair[1]):
+					await self.send({'Name': self.sud.name, 'Description': self.sud.description})
 
 	async def send(self, data):
 		await self.msg_handler.send(data)