Add a first implementation of a Bloom filter.

The Bloom filter is not producion ready.
It is not aware of the garbage collection, i.e. it is not removing
old entries. This increases the false positive rate over time.
And it is not crash safe.
However, it is fine for experimental usage.

Signed-off-by: jkaiser <jkaiser@kaiserj-2.zdv.uni-mainz.de>
Better handling of invalid usage of the chunk locks.

Signed-off-by: jkaiser <jkaiser@kaiserj-2.zdv.uni-mainz.de>
Add more profile information to the filter chain.

Signed-off-by: jkaiser <jkaiser@kaiserj-2.zdv.uni-mainz.de>
Add a bit of profiling for the chunking in the content storage.

Signed-off-by: jkaiser <jkaiser@kaiserj-2.zdv.uni-mainz.de>