Convert .awsboxen.json into easier-to-maintain YAML files
Script creation of basic cassandra cluster.
Refactoring the awsboxen deployment scripts.
Add basic loadtest scripting.
Include some basic loads-runner boxes in the awsboxen deployment.
Split up the loads boxes into their own cloudformation template.
Avoid race-condition between cloudinit and rc.local

Probably there is a better, cloudinit-approved way to achieve this.
But my quick hack will do for now.
Tweak loadtest setup for latest upstream changes.
Use pre-computed credentials for most loadtest operations.

This means we don't have to do the password-stretching at runtime,
giving much improved throughput on the loadtests.