The process can now indicate the agent structure can be garbage collected, saving a wait for a timeout. This
is typically hapenning when archive jobs need requeueing after a session hits the end of the tape.

The garbage collector now sets a flag on the agent object indicating garbage collection.
The process will immediately exit when detecting garbage collection.

Queueing of Archive jobs now use the ContainerAlgorithms instead of the methods in the ArchiveQueue object
Created a base class (interface) that allows to add and remove object(s) from the ownership of an Agent (implementation : AgentWrapper) or from an AgentReference (implementation : AgentReference)

Queueing of Archive Jobs is done and unit tested
Queueing of Retrieve Requests is not completely done yet

Refactored OStoreDB::RetrieveMount::batchSucceedRetrieveForRepack() method

Some typo fixes.

In order to be efficient, the data (tape status and queue sizes) is cached in memory.
This function needed access to the catalogue (where the tape status is located).
This in turn required passing the catalogue object to:
 - The garbage colletion functions for all object types.
 - The garbage collector object now keeps a reference to the catalogue.
 - The path to the catalogue credential file should now be passed to cta-objectstore-collect-orphaned-object
 - The OStoreDB also needs a reference to the catalogue in order to queue retrive requests.

 The garbage collection member function are now also being passed a log context, so the requirement for better
 log of object fate can also be fulfilled later. This in turn required the passing of a logger object to
 the object store and relative helper classes.

 Finally, a dummy catalogue class has been created to be used in unit tests.

This required to pass an AgentReference through to all garbageCollect() member functions of all objects.
The changed behavior required adaptation of the corresponding unit test (the archive queues now need to
be properly referenced in the root entry).

Added missing garbage collection for all object types.
Added logging to AgentHeartbeat.
Some object types still miss garbage collection implementation.

AgentReference::{addTo|RemoveFrom}Ownership() are used instead.
Fixed typo in function name.
Added missing lock in AgentReference::queueAndExecuteAction().

The queue is housed in the AgentReference class. It currently covers the add to ownership
and remove from ownership operations. This queued system guarantees in-order execution
of operations.

Agent becomes a usual class, like any other in the object store.
Object name generation (agent's and others) is now handled in the separate AgentReference.
The previous situation created race conditions.

ObjectOps by adding a second parameter to the template.

Thanks to Steve Murray for findind the solution.

Partial implementation of per object type dump.

The agent now carries its own timeout (defaulting to 60s).
The unit test now validates that the 2 agents were cleared from the agent register.

Added support and unit test for object creating calls in RootEntry (DriveRegister, TapePool, AgentRegister)

Renamed the setName/GetName functions to the more appropriate getAddress/setAddress.

License comment is no longer filtered out by doxygen when generating web pages of the individual source files.

Implemented the self registration and unregistration functions for the agent.
Improved the safeguards and imlpemented more initialize() function for different object types.

and created initial unit tests for those.