ActiveSupport::TaggedLogger should tag each line of output

```ruby
logger.tagged("REQUEST-XYZ") { logger.info "Hello\nWorld!" }
```

outputs

```
[REQUEST-XYZ] Hello
World!
```

It would be better to output

```
[REQUEST-XYZ] Hello
[REQUEST-XYZ] World!
```

Otherwise, in a distributed environment, you don't know which request generated the second line.