move from AR to Sequel

I still love AR, but lets see how Sequel works out for us
add in activesupport (it's needed)
username not user
with_connection is no longer being used
log_id not log.id
where is so much nicer than filter
update aggregation to work with sequel
oops, wrong service class name
make sure the dataset is run
remove using multi_json as we are using json decoding directly
correct the error message
add a little logging when aggregating