Added participants new metric to qaforums repositories data.
Added new top metric messages_sent to qaforums tops.
Added studies to be executed (just onion now).
Improved Onion study so it works with get_agg API and could be added to general agg data in SCM.
Fixed formatting.
Removed Onion from studies in SCM. Now it is executed in a generic way configurable
in automator.
Fixed studies data gathering logic.