Add Riak Control test.

This test produces *failing* cases for Riak Control against to cut 1.4.1
release, but passes when run against a tentative master-based 1.4.2
build.

This test currently covers:

* Rolling upgrade of all nodes, while every node runs control.
* Verifies nodes do not fail during the rolling upgrade.
* Verifies two releases back.
* Verifies that 1.3+ resources return properly and deserialize.
* Verifies 1.2 partitions, overview and cluster resource.

This test does not cover:

* Intermediate state checking: this will not verify that halfway through
  an upgrade some of the nodes will show as incompatible.
* Final state checking: verifying that all nodes return a valid status
  once they hit current.
* Riak 1.2 node stats and ping resources.
* Riak 1.2 deprecated fallback resource, which isn't used in the UI.