Don't delete stacks indiscriminately
Don't delete stacks indiscriminately

Assume a rollback stance when stack launching fails: if the failure
occurred during creation, delete it; during resuming, suspend it.

For clarity, also separate the stack launch status from the verification
status as much as possible.

TG-3 #closed

arbrandes/hastexo-xblock,arbrandes/hastexo-xblock,arbrandes/hastexo-xblock,arbrandes/hastexo-xblock,hastexo/hastexo-xblock,hastexo/hastexo-xblock,hastexo/hastexo-xblock,hastexo/hastexo-xblock,arbrandes/hastexo-xblock