Fixed missing permanent logging of the TPVID in tape thread: it was wrongly included in a local set and deleted at the end of the local scope.

Added delay to ensure the last reported stats have enough time to get processes by the initial process before the session process exits.

Removed leftovers of special case snprintf call for double, now that snprintf is the default for doubles.

Modified initQueue timeout to 30 seconds instead of 5 minutes. The issue is that in case of network issues, such a long timeout may make the diskmanagerd stuck during too long while it is preferable to fail fast.

Modified the clients replier thread to work as a thread pool, with DiskManager/NbClientRepliers from castor.conf being the number of threads

CASTOR-4823: tapeserverd's main process should log statistics and status of the closing session in all cases

Added new messages between the session process and the main process: addition and removal of log parameters.
Added storage of the log parameters in the catalogueTransferSession.
Added logging of the tape session at the end in the initial process, allowing statistics gathering even in
case of crash. This standard log message is intended to be used as an input for the tape log system.
Changed the default off the formatting of doubles in the log so that we don't end up with hard to parse
scientific notation in the logs.

Introduced a pool of connections for the transfermanagerd, configured by the TransferManager/NbDatabaseConnections parameter. Also moved the nb of worker threads from the command line to the TransferManager/NbWorkers parameter in castor.conf.

Fixed race condition when creating and dropping DB connections. This was exposed by stress tests and the culprit was that any client wanting to inspect this class by calling hasattr() would have called getattr(), which internally creates a connection

Conflicts:
	h/Ctape_constants.h
	tape/cvtden.c