Reintroduced delete batch
Added duration label to s3 persistence logging
Added time logging to aggregator
Added threading pools
Simplified delete_messages
Fixed problem when delete queue is empty
Added data importer
Added bounding box coverage algorithm
Added dynamodb aggregator
Updated frontend to pull from dynamodb
Added error logging to dynamodb persistence
Abstracted base class for datahandler
Added dynamodb table to settings, created readings_stats view
Dirty fixes! #78
Updated html/js for stats data #77
Merged develop in