Simplified exception messages of the smart pointers of the tape::utils package.  This will help us use the code in the mighunter.

if it is not, any other part of the application may still submit
tasks to the queue to wake up the consumer threads.

Introduced the singleton pattern to enforce that there can only be one copy of the aggregatord daemon in a single process

be applied to the mighunter as we are making the code bases use the same
concepts.

+ minor cleanups

if the castorFile link is available, use it and send the fileId, otherwise
just send the fileName

Fixed bug #61552: broken stager_qry -n -r (i.e. query per reqId, with getNext flag) for prepareToGets

net::createListenSocket().

Added more tests for invalid socket descriptors to the net package.

net::acceptConnection exception messages.

due to a bad file listen socket file descriptor and RINVAL due to the listen
socket not actually being a listen socket.

socket-descriptor is valid.

log messages where it was known.

Improved log and error messages by replacing RCP with remote-copy.  Now all messages should use remote-copy.

should have used "client".

Modified the castor::tape::net::createListenerSock in order to throw castor::exception::Exception and not only castor::exception::Communication.

should not be able to make copies of its objects.

them to help cross reference the aggregatord log with the tape gateway log.

Fixed the getSchedulerJob procedure which was not listing jobs if no filesystems were available in the target service class

to find a slow file-descriptor leak.