This allows multiple processors to exist within the frontend, i.e. one
for handling EOS WFE requests and a different one for handling Admin
requests.

This allows specifying different protocol buffers for EOS and CTA Admin
messages, both of which must be processed by the same XRootD plugin in
the CTA Frontend.

This library contains the protobuf which defines the API for the CTA Frontend.
This will define messages for the CTA admin tool as well as EOS so EOS should
not be part of the library name.

Conflicts:
	cta.spec.in

To activate this option run CMake with:

$ cmake -DBUILD_XROOT_SSI=1 ../CTA

Especially, in OStoreDB::fetchMountInfo(), some operations were not lock free where they should have been.

Proceed all successful reports asynchronously and periodically check
and clear statuses if they have finished.
In the end of session do the check/flush for all reports in the
successful reports queue.

Switch from synchronous rados remove to async aio_remove in
case of zero size object in BackendRados::AsyncUpdater

Conflicts:
	objectstore/ArchiveRequest.cpp
	scheduler/OStoreDB/OStoreDB.cpp
	xroot_plugins/XrdCtaFilesystem.hpp

As those fuctions are usually called in a tight loop at the end of the session or in the garbage collector,
they tend to unlock and relock the queues immediately, and sitting on the lock for a long time in practice.
The added sleep will increase the odds of other processing slipping in between the unlock and the lock.

The ping() and queueRetrieve() timings are of interest, so commit now.
The rest of the timings will follow.

Use precision .00 for Mbytes. Move library name to the front.

This led to failure to requeue non-handled jobs at the end of a tape session (and leave them
to garbage collection.
Also added timings.

Removed all instances of RetrieveMount::getNextJob() and siblings.
Fixed incomplete deserialization of archive file in RetrieveRequest::asyncUpdateOwner().