rename scripts to be more clear
Rework code based on feedback:

1. Create ReactorResult class to manage both the result from SNS and
    any suppression filtering
2. No longer have any tryagain logic in get_result()
3. Fix YYYYMMDDHHMMSS parsing
4. Make ReactorSuppress a base class for future non SDB data stores
5. Various variable renaming/documentation cleanups
6. Use aws_helper ConnectionManager
6. Rename nymms* scripts to be suppression, not filter