* make the different values influencing the compaction run configurable
* Compaction statistics handling
- we mustn't keep the number of dead objects on the compacted datafiles statistics, else it will be compacted again.
- keep statistics of the compaction runs on the DatafileStatistics object
- add the new statistics on DatafileStatistics to the figures api
- implement test that assures only one compaction is run, and the statistic values are maintained
* don't mention the version number
* Implement review
- fix documentation
- allow 0 maxfiles to enable users to disable combined of datafiles
- add statistic element that counts the number of combined datafiles
* Implement review
- fix documentation
- use locks to make statistic values consistent.
- fix typo in variable name
* fix temporary variable unnecessary.
* changelog
* simplify index API a bit
* fix fulltext index removal performance, simplified code
* updated CHANGELOG
* fix hanging test
* try to fix shutdown problem
* improve fulltext query performance
* fixed duplicate var
* removed obsolete code
* fix some shutdown races
* do not call ensureIndex that often