Done.

The WrongPreviousOwner exception has been moved out from archive and retrieve requests to have more generic code.

Exits from Init() with exit(1) in case of failure instead of returning
false, as a temporary workaround until the following XRootD bug is
fixed:
https://github.com/xrootd/xrootd/issues/751

Done

Created conrresponding unit test.

Added more information to ContainerTraits<ArchiveQueue> to avoid querying the archive request object.

Upgraded to EOS 4.2.24-20180614121622git0cf4285 which has the fix for compactions slowing opens for read