Auto-create the SimpleDB domain

The wiki instructions have a very complicated workaround for the fact that there's no
good CLI tool for SimpleDB.  Rather than do that, let's just auto-create the SimpleDB
domain if it doesn't exist.

This makes it much easier to get going with Chaos Monkey!
Log ChaosType
Don't try to create a SimpleDB domain if we're not running on AWS

VSphereClient pretends to be an AWSClient, but doesn't do so very fully...
Tolerate (but warn) on failures auto-creating SimpleDB domain

To keep the unit tests happy
Merge branch 'pluggable_chaos_type' into simulate_ebs_failure
Merge branch 'simulate_ebs_failure'
Merge branch 'auto_create_simpledb_domain'