Just some quick fixes to address some problems.

1) Seriously dicreased the number of threads.
2) Fixed singleton pattern
3) Turn the isUrlBroken to static, to avoid to many objects creation
4) Used Jsoup and its bodySize limit feature to improve performance
Split domains with more than 100 urls to batches with 100 urls, in order to be processed by 1 thread of our pool
Merge pull request #1 from apsegian/master

Just some quick fixes to address some problems.