Moved TapePool from common::dataStructures:: to catalogue:: because it belongs to the Catalogue interface

Fixing the fluctuations in the archived file count that are due to the automatic deletion of disk replicas in the workflow.

Conflicts:
	objectstore/BackendRados.hpp
	objectstore/BackendVFS.hpp
	objectstore/GarbageCollector.cpp
	objectstore/GenericObject.cpp

Some typo fixes.

This ensures we will not fail to grab a lock in case a process dies.

This led to garbage collactor segfaults.

This allows previously developped asyncLockfreeFetch to apply to it.

The previous strategy was made under the assumption that we needed to lock sparingly.
With the introduction of lockfree strategy, this is not true anymore.
The new strategy will be immune from the A watches B, B watches A, both die, and
no one garbage collects them situation (also called cyclers in utility cta-objectstore-unfollow-agent).

This will remove contention on the drive register as drives uipdate their statuses.
Also simplified structures in OStoreDB implementation (less references with added friend relations).