Merged all changes made from 0.7 into the trunk.

Removing sensitive data from the cluster is not currently working.
Security group name no longer includes the region.
Re-added code to delete init scripts from cluster machines after they have executed.
Deleting commented out code.
Fixed broken unit tests. No longer trying to delete init scripts for the DestroyCluster action.
Using new version number for custom build.

Switched to use custom clouds build.
Merge pull request #2 from rescale/migrate-to-trunk

Migrating rescale 0.7.1 changes into the trunk.