Add implicit dump until level

Typical configuration for logging is 

``` js
{
   "logLevel": "info",
   "dumpLevel": "error"
}
```

This would make INFO level log print twice.

Proposed solution: 

When dumping logs print until (logLevel - 1) level i.e. in this example, all log entries with levels ERROR, TRACE, DEBUG will be printed when dumping the logs and not INFO.
