Adding the attributes to nodes.

Change-Id: I2d93033c85d3e547f4c26813163ba5bfd8d7c815
Signed-off-by: dekehn <dekehn@gmail.com>

Adding the node attribute code.

Attributes are the properties that attach to the nodes in the
MODB, which provide the Node its characteristics and statuses.

Change-Id: Ibe4ef79ef2bbff986a3f984d16b8867452b7a4d2
Signed-off-by: dekehn <dekehn@gmail.com>