Some Fixes and Improvements

* Fix several typos in log messages. And some test on the matter as well
* Add comment to `AbstractPersistentAcceptOnceFileListFilter.rollback()` to clarify the reason of `rollingBack` variable
* Make `RemoteFileTemplate.StreamHolder` as `static` to avoid extra internal variable to outer class instance
* Replace `MessagingException` with `AbstractInboundFileSynchronizingMessageSource` in `init()` method of some components. It isn't Messaging yet in that phase
* Fix `SubscribableRedisChannel.MessageListenerDelegate` to handle `Object` not `String`, because with the `serializer` injection there is no guaranty that incoming is always `String`
* Move `JSch.setLogger(new JschLogger());` in the `DefaultSftpSessionFactory` to `static` block. It really should be done only once
* Remove `Assert.isTrue(this.port >= 0)` from the `DefaultSftpSessionFactory`. The subsequant `initJschSession()` convert it to default `22` port
* Change in the `JschProxyFactoryBean` `UnsupportedOperationException` to `IllegalArgumentException`. Wrong enum is wrong argument. That isn't a problem of operation
* Simplify `stop()` in the `CuratorFrameworkFactoryBean` and mark it as a `this.running = false`. Otherwise it wasn't able to be restarted
* Expose `leaderEventPublisher` in the `LeaderInitiatorFactoryBean`  and fix `stop(Runnable callback)` with propagation `callback` to delegate.

Fix `SubscribableRedisChannelTests` for new `handleMessage(Object)` signature

spring-integration-redis/src/test/java/org/springframework/integration/redis/channel/SubscribableRedisChannelTests.java

@@ -99,7 +99,7 @@ public class SubscribableRedisChannelTests extends RedisAvailableTests {
 		MessageListenerAdapter listener = channelMapping.entrySet().iterator().next().getValue().iterator().next();
 		Object delegate = TestUtils.getPropertyValue(listener, "delegate");
 		try {
-			ReflectionUtils.findMethod(delegate.getClass(), "handleMessage", String.class).invoke(delegate,
+			ReflectionUtils.findMethod(delegate.getClass(), "handleMessage", Object.class).invoke(delegate,
 					"Hello, world!");
 			fail("Exception expected");
 		}