Rewrite the Crowbar CLI for CB 2.0

This pull request gets rid of a lot of obsolete code, and starts
exposing all of the core Crowbar models via the API and the new CLI.

What is new:

* Vastly less boilerplate.  Despite exposing much more than the original
  API does in CB1, this code as 1500 lines shorter.  That gap will close
  as missing features are added back.
* Improved ease of extensibility.  Most simple commands are inferred
  from class names and methods, and I plan on expanding that to
  inferring argument driven keywords from method names.

What is still missing:

* Help.  What is there is very basic.
* Loading barclamp specific functionality.  Right now, I am putting
  everything in a single file for ease of hacking.  That should change
  to allow barclamps to provide libraries that implement
  barclamp-specific functionality.
* Completeness. I have only mapped out the parts that are useful for
  cluster bringup, some demoing, and some exploratory work. I have not
  evaluated all the routes and wrapped them in the CLI.
Merge pull request #802 from VictorLowther/pull-req-master-1abc8dac24f11b2f9151ad65e0ce1c29424b8e4b

Rewrite the CLI for Crowbar 2 [1/2]