- change the SyncManager to retry MANUAL syncs that encounter a soft error

- make the sync dump handle the case where there are no accounts
- fix a bug that caused the SyncManager to burn up CPU in the system process

The following was implemented:

scheduler offers:
 - settings to disable sync
 - retries of certain errors
 - backoffs

want a way to control these when scheduling a sync
 - "ignore_settings"
 - "ignore initial backoff"
 - "manual" : ignore settings, ignore initial backoff
 - "do not retry"

- need to change the default behavior of not retrying manual syncs to retry regardless