Remove all synchronization from OutputFormats and docs for that.
Small formatting fixes.
Set number of worker cores to 1 to prevent bz2 decompression problems
Revert "Set number of worker cores to 1 to prevent bz2 decompression problems"

I mistakenly thought that "spark.cores.max" means max. number of cores per worker. It's actually max. cores to use in the whole cluster.

This reverts commit 87f1743ebe330700d68f07e6196fc8c449178a74.
Merge pull request #30 from dbpedia/output-nothreads

Remove all synchronization from OutputFormats