Updated seeding to reflect new design
Renamed Fee to Transfer
Removed direct link to User.fee_collector
Fixed dangling reference to investments.category
Removed remaining reference to Fee
Usernames
Added Position#long/short
Refactored fill strategies
FillStrategies#tax_efficient_harvester
Removed generate_activities! from factory.  Evil pattern!
Renamed GenerateActivities to GenerateActivitiesWaterfall