use libcephfs jar from maven central

Signed-off-by: rootfs <hchen@redhat.com>
review feedback

Signed-off-by: rootfs <hchen@redhat.com>
relocate core-site.xml

Signed-off-by: rootfs <hchen@redhat.com>
update glusterfs setup doc

Signed-off-by: rootfs <hchen@redhat.com>