Removed the xroot devel packages from the listing of installed rpms because the reader was not requested to install them

Checking the accessibility of the mock name server base path in each method (of the mock name server) and reporting meaningful error

PLEASE NOTE THE FOLLOWING TWO ADDITIONS:

For the EOS rpms create the /etc/yum.repos.d/eos.repo file with the following contents.
  [eos-citrine]
  name=EOS 4.0 Version
  baseurl=http://dss-ci-repo.web.cern.ch/dss-ci-repo/eos/citrine/tag/el-6/x86_64/
  gpgcheck=0
  enabled=1

Make sure the following entry exists in xrd.cf.mgm so that the EOS namespace
plugin will be loaded in.
mgmofs.nslib /usr/lib64/libEosNsInMemory.so

Fixed minor documentation details.

Removed my own hardcoded plugin library path in the xroot configuration file and updated instructions to create appropriate soft links

Homogeneize the naming: removed mixtures of archival and archive in favor of the latter. Same the retriv{e,al}.
Renamed file transfers to tape jobs as a single file can required several jobs (in the case of nultiple copies).

Changed name of keytab file in configuration and added xroot server documentation in the latex document