Store good MAC's and interfaces in node_info after processing

This makes life easier for post-processing hooks and removes need
to pass valid_macs to _process_node.

Change-Id: I49191290b7941e88f7fcb25dba6a324e21acb63c
Separate validating NIC data into a new plugin

This continues effort started in blueprint plugin-architecture
to minimize discoverd core.

Change-Id: Iee423678445ba2d282633bb2b44389acbdeb5adb
added an eDeploy plugin

It can talk to an eDeploy ramdisk to discover hardware.

Change-Id: I11b4cf21ec81ce8efd3222597a5226fe260721e2