Remove ancillary data
When running in environments where you don't want an accumulation of data it is desirable to remove ancillary data (such as used by Polymer) after running. This has been implemented for removal of input satellite data but is more complex for ancillary data as the file paths are not currently returned so it is challenging to identify what has been downloaded. This needs to be done in a way that multiple Sencast instances can be run simultaneously and not delete data needed by another instance.