add market order to api document
add order id indices to trades
record funds received
Revert "Revert "refactor Order#avg_price""

This reverts commit d6bdccf455adad481cc6c8cab060686d9e0620f6.
calculate Order#avg_price using funds_used and funds_received
add migration task for new column Order#funds_received
fix AMQPConfig#channel
concurrent pusher daemons
optimize trade executor subscription
optimize order processor subscription
Merge branch 'master' into api-optimization