The logging implementation is not thread-safe

Running IlluminaBasecallsToFastq with multiple threads lead to garbled log file. It's easy to see if we set VERBOSITY=DEBUG:

INFO	2014-06-02 08:48:38	IlluminaBasecallsToFastq	READ STRUCTURE IS 75T1S6B75T1S
DEBUG	2014-06-02 08:48:46	IlluminaDataProviderFactory	The following parsers will be used by IlluminaDataProvider: 
DEBUG	DEBUG	2014-06-02 08:48:46	IlluminaBasecallsConverter	Reading data from tile 11206 ...
2014-06-02 08:48:46	IlluminaDataProviderFactory	The following parsers will be used by IlluminaDataProvider: 
DEBUG	DEBUG	2014-06-02 08:48:46	IlluminaDataProviderFactory	The following parsers will be used by IlluminaDataProvider: 

The reason is that the synchronization on 'this' is not enough since there are multiple loggers writing to the same stream (System.err). Synchronizing on 'this.out' seems to solve the problem.
should this not be synchronized?  This could then be taken out of the if/else