Improved exception handling

[Zeebrow]

Exceptions need to be handled accurately and consistently. (I started handling them after the app was pretty much done)

• logger should emit debug if the action did not produce an exception
• warning when action didn't do what it was intended to, but should not stop the app from finishing its operation
  • e.g. a security group doesn't exist when we go to destroy it
• error when action didn't do what it was intended to, and app should not continue its operation
  • e.g. IAM permissions
  • generally seem to be caught in AWSApp.py as opposed to specific resources

There's too many to count at this point. Mark 'em as you see 'em.