Split source tarball creation from rpm-pkg target
so it can be used from deb-pkg target as well. As
added bonus, we can now pretty print TAR the name of
tarball created in quiet mode

This patch prepares the groundwork for deb-pkg source
package adding bit.
Signed-off-by: NRiku Voipio <riku.voipio@linaro.org>
Signed-off-by: NMichal Marek <mmarek@suse.com>