This is a TEMPORARY modification to the  CTA front end.

When an "eos rm" command is executed the xCom_deletearchive()
method of the CTA front is called.  Before this commit the
mthod would try to removed the archive file from both the
object store and the CTA catalogue.  This took more than 15
seconds to complete under som ecircumstances.  This commit
removes the call to the object store.

Please note that this commit will causes a leak in archive
files.  If a file is "in-flight" and therefore has not yet
been written to tape and recorded in the CTA catalogue
then a call to "eos rm" will do nothing and the file will
eventually appear in the CTA catalogue when it is written
to tape.  The file will therefore NOT be in the EOS
namespace but it WILL be in the CTA catalogue.

This lead to a lapse moment when a mount was not wisible, and other drives tried
to mount the busy tape.

sessions.

Related to 6824973c but now it will
calculate the speed between two updates and not an average tape session
speed.

threads.

Fill creationLog for archive and retrive requests in the frontend
with actual data.

Scheduler will use real data for the requests creation time.

drive.
Change frontend reporting for the current stats from bytes to Mbytes and
from bytes/s to Mbytes/s.

If the "cta af ls" command is executed and the listing
encounters duplicate tape copy numbers then the listing
continues with "workaround" number displayed in place
of the duplicates and inow with this commit a log
message is alseo written to

    /var/log/cta/cta-frontent.log

An example log:

2017-07-12T18:04:40.691236+02:00 itdssbuild01 cta-frontend: LVL="Warn" PID="9423" TID="9436" MSG="Found a duplicate tape copy number when listing archive files" archiveFileID="5" duplicateCopyNb="1" workaroundCopyNb="2" vid="V41001" fSeq="5" blockId="41"

recall tape transfer session.

TaskWatchDog pereodically update Object store information with
current values for the tape session stats.

If the drive is set to force down mode, we stop finding new jobs and let the current session drain.

The typo made Vlado's eyes bleed.

This will help diagnose failure to honor maxDrivesAllowed.

The queue is now fully event driven: a write to object store will start as soon as the previous one completed (if any).
The notion of timeout and max number of elements before flush has been removed. This harmonises the mechanism with the
one used in MemArchiveQueue::sharedAddToArchiveQueue() (see a591129c).

This constraint prevents a tape server from writing the same file
more than once to the same tape.  We should actually allow this
to happen so that we can tolerate the pathological case of a
cta-taped daemon crashing immediately after inserting a row into
the TAPE_FILE table and before updating the object store.

Implemented GarbageCollector::reinjectOwnedObject() and called it on garbage collector shutdown.
This fixes the issue of non-empty garbage collectors exiting.

Simplifies code and avoids unnecessary string copy construction

We now only do one queue update at a time (per process). While one batch is being pushed to the objet store, the
following one is being built up, and written as soon as the previous write completes. This can be see in the timings from
the logs of the unit test OStoreSchedulerDatabaseTestVFS/SchedulerDatabaseTest.createManyArchiveJobs/0 here:
[...] MSG="In MemArchiveQueue::sharedAddToArchiveQueue(): added batch of jobs to the queue." objectQueue="archiveQueue-[...]-68" sizeBefore="0" sizeAfter="1" addedJobs="1" waitTime="0.002403" enqueueTime="0.036594"
[...] MSG="In MemArchiveQueue::sharedAddToArchiveQueue(): added batch of jobs to the queue." objectQueue="archiveQueue-[...]-68" sizeBefore="1" sizeAfter="100" addedJobs="99" waitTime="0.036547" enqueueTime="0.001629"
[...] MSG="In MemArchiveQueue::sharedAddToArchiveQueue(): added batch of jobs to the queue." objectQueue="archiveQueue-[...]-174" sizeBefore="0" sizeAfter="1" addedJobs="1" waitTime="0.000058" enqueueTime="0.061447"
[...] MSG="In MemArchiveQueue::sharedAddToArchiveQueue(): added batch of jobs to the queue." objectQueue="archiveQueue-[...]-174" sizeBefore="1" sizeAfter="198" addedJobs="197" waitTime="0.061434" enqueueTime="0.001431"
[...] MSG="In MemArchiveQueue::sharedAddToArchiveQueue(): added batch of jobs to the queue." objectQueue="archiveQueue-[...]-174" sizeBefore="198" sizeAfter="200" addedJobs="2" waitTime="0.000840" enqueueTime="0.037259"