Initial DDF support code.

Create a ddf array by naming the device /dev/ddf* or
specifying metadata 'ddf'.

If ddf is specified with no level, assume a container (indeed,
anything else would be wrong).

**Need to use text_Version to set external metadata...

More ddf support

Load a ddf container.  Now
   --examine /dev/ddf
works.
super-ddf: fix compile warning

From: Dan Williams <dan.j.williams@intel.com>

super-ddf.c:723: format %lu expects type long unsigned int, but argument 3 has type unsigned int

Signed-off-by: Dan Williams <dan.j.williams@intel.com>