Add other S3 endpoints, per review by coryb
Ensure default for all new strategies is disabled

Avoids surprising users.  Thanks coryb!
Check for isEnabled before check canApply

Means we don't need to be as quiet in canApply.

Thanks coryb!
Don't try to use BlockNetworkTrafficChaosType on non-VPC instances

It's cheap to check if an instance is VPC, so do check!

Thanks for the suggestion coryb.
Refactor a strongly-typed wrapper around cloud, instance & ssh config

Used to cache SSH connection state.
Merge branch 'more_chaos_types'