Fixes https://github.com/spring-projects/spring-integration/issues/2974 There is a race in that we could get a `SocketException` in `inputStream`. Since this is between payloads, it needs to be thrown as a `SoftEndOfStreamException`. * * Add javadocs to SoftEndOfStreamException * * SEOSE is now a RuntimeException (can't be an UncheckedIOException - no default CTOR