add config include files for storage backends

Different configuration backends require different configurations.
With this patch, backend specific include files can be installed
at /etc/bareos/bareos-sd.d/.
If they should be used, they have to be included in the main configuration file.
The configuration files bareos-sd.conf and bareos-dir.conf
have been twice in git. One version is replaced by a link.

Signed-off-by: Marco van Wieringen <marco.van.wieringen@bareos.com>
Rebuild configure.
fixed packages dependencies

Required dependencies are determined automatically by build process.
Add missing bareos-storage dependencies.

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