Command call should log the stdout and stderr

Our utils.execute method did not log the stdout and stderr message
for command call, for these message, they are required for us to
track command call stdout and std error in details.

Change-Id: Ibfb15c3a004f1c2c091e59f452ebaaceeebd934d
Closes-Bug: #1242544
Add driver interfaces validation

This patch will expose a /nodes/<uuid>/validate subresource where users
could GET to trigger a validation on the 'core' and 'standardized'
interfaces for the driver the node loaded with. This will expose a way
to the ironic driver in nova to validate the driver interfaces of a node
before deploying it.

Change-Id: I1ca2b17c9752e7593214fe5b044595f6e63bed18
Fix auto-generated REST API formatting

Fix an issue we have with the formatting of our auto-generated
REST API documentation. Sphinxcontrib-pecanwsme does not like
single-line method doc strings.

This patch adds some description of the RESTful parameters.

For methods that take no parameters (eg, get_all) it simply
converts the doc strings to multi-line, even though this does not
adhere to PEP257. This is a work-around for a bug.
  https://github.com/dreamhost/sphinxcontrib-pecanwsme/issues/8

Change-Id: I0fde3314bf2d5c3e109ec85626d3e509ffd53c7c
Developer doc index page points to correct API docs

The index.html page of our developer web docs should now
reference the auto-generated API documentation, and we can
remove the out-of-date hand-written api-spec-v1.rst.
It served us well early on, but is impractical to keep up
to date with a fast-moving project.

Change-Id: Ie71f43ef363501d4c470485a011267755f41c5b3
Merge "Fix auto-generated REST API formatting"
Merge "Developer doc index page points to correct API docs"
Merge "Command call should log the stdout and stderr"