Fix Cryptsy Broken By Removal Of Trade Id

Looks like some time today Cryptsy removed the 'id' field from their public trade object.  This causes retrieval of currency pair / market ids to break with a NPE.  This change removes that field.

I've sent an email to Cryptsy support to see if it was intentional or not.

Also, updated hitbtc public trade history with a last id and made itbit more flexible for supplying a sinceTradeId via any Number type.