NVMe over Fabrics support for nvme-cli

[Keith Busch]

On Tue, Jun 07, 2016 at 02:42:48PM -0400, Keith Busch wrote:
> Happy to get fabrics in now as I have new features I'd like to add very
> soon, and didn't want you to have to rebase again. The new features are
> vendor extentions and json output. I'll post them to the linux-nvme list
> first in case anyone is interested in reviewing.

Not quite ready to my latest, but I pushed it to a different branch here:

  https://github.com/linux-nvme/nvme-cli/tree/experimental

It adds a "--output-format" option that takes normal, json, or binary types.

The main thing though, is support for plugin extensions, and I made LightNVM
and Intel built-in extensions with specifics to their devices.

It also adds support for dynamically loaded plug-ins. This is so a
3rd party or vendor can extend the program without having their stuff
in-tree. It accomplishes this using the dynamic linking loader (dlopen,
dlsym, and friends) to open and register symbols.