First activity!  Real bids placed!

Replaced order hash with Order object, type-verified certain values
Completely reworked order chain, hypothetical > working > filled
Simplified order book functionality, removed bid/ask duality
Added order quantity calculation to hypothetical order creation
Added checks for orphaned orders that might not be recorded (i.e. crash)
Adjusted trading class to understand Order objects instead of string parameters
Integrated account balance with hypothetical order creation
Added order book display to front end
Code cleanup
Bug fixes