added debian/copyright file

Added debian/copyright file, generated from LICENSE file.
Debian policy requires that the file debian/copyright is part of the source
and not generated during build.
LICENSE: moved fastlzlib, fastlz and lz4 to section 1e
to clarify, that these are additions to the original Bacula license.

Signed-off-by: Marco van Wieringen <marco.van.wieringen@bareos.com>
build bareos-storage-glusterfs packages on RedHat

RHEL7 includes current glusterfs packages,
therefore the Bareos GlusterFS backend is build on this platform.

Signed-off-by: Marco van Wieringen <marco.van.wieringen@bareos.com>