This is a port of downstream inspector ramdisk plugins we found helpful.
* logs - sends journald logs with inspection data.
* extra-hardware - uses hardware-detect utility to collect bigger
  hardware inventory and to run benchmarks.

Change-Id: If05402606c45185d618279eef46e68c51209f82b

If an image cannot be downloaded for some reason, it is helpful for
operators to have the image path, checksum, and calculated checksums
available easily from the API.

Change-Id: I6a2fb46726245cebd730b5c51d4f25f8465f1658

Currently we only use these disk properties for root device hints.
However, they'll be really useful for inspector, especially for also
implementing root device hints.

Change-Id: I48aa6b6d2d198d16f2f8e387970f7230066cf8a2

1. cleanly separate deprecated and non-deprecated properties
2. add root disk to inspection data, so that we can have a proper
   fallback when root device hints are not given.

Change-Id: Ie19b82ff2a914873ff4b2395b02643e086b934b1

Change-Id: I7ec05e501ec40802efa14cabe14752972919c7a9

Create a SerializableComparable class derived from the Serializable
class.

Added the following functions to the SerializableComparable class:
  '__eq__'
  '__ne__'

Disable the '__hash__' function in the SerializableComparable class as
some derived classes are mutable.

Use the SerializableComparable class in hardware.py and
extensions/base.py

This should make unit testing users of the class easier when doing a
self.assertEqual() or self.assertNotEqual()

Added some initial unit testing for encoding.py

Change-Id: If0f14b3bfe7f1391f65dd730a16a534afed0da82

If a clean step returns a tuple (like the output of
processutils.execute), WSME raises an error about the type. Casting
the result as a list seems to make it work. This is almost certainly
a bug in WSME, but after digging a bit I couldn't find one.

Change-Id: I91cb7a989ab56c0942469e03937945d4a590ad95
Partial-bug: #1493554