Fix a syntax error in the .ycm configuration
Fix an error in the item counting while dropping pinned entries.

The pinned entries have been dropped correctly, but they have not
been removed from the dirty item count and the total item count.
Work on the statistics maintainance of the block chunk cache.
Add a none garbage collector, which only updates the block hint.

The usage count garbage collector is inherently at odds with
a sparse configuration.
Fix zerochunk unit test.
Work on the chunk importing with respect to the sparse changes.

In the old configuration, the dirty start of the chunk index imported
all entries in a container.
We now maintain in the container a flag if the chunk is expected to be
in the chunk index.
This flag can later also be used in dedupv1_check and so on.
Fix the emission of the log empty event.

If the replay id has been fully written, we should write the log empty
event.