Bug 6278: Move opendaylight-karaf-empty to odlparent

Move opendaylight-karaf-empty from controller to odlparent.  As with
moves of other artifacts, the following process will happen:

1) Copy opendaylight-karaf-empty into odlparent and adjust the groupId.
   This patch handles the copy work.

2) Change opendaylight-karaf-empty in controller to derive from
   odlparent's opendaylight-karaf-empty

3) Change references to use the artifact added in #1.

4) Deprecate and remove controller's opendaylight-karaf-empty.

This patch just handles the initial groundwork outlined in #1.

Change-Id: I824e61280784409194840ba54bdc0a6a10f0368f
Signed-off-by: Ryan Goulding <ryandgoulding@gmail.com>