Added Asset Exchange related APIs:
getAskOrder, getAskOrderIds, getBidOrder, getBidOrderIds,
getAccountCurrentAskOrderIds, getAccountCurrentBidOrderIds.
great, thank you very much for adding these new calls jean-luc, the core
is going better and more stable every day, i really appreciate your work.
getAccountCurrentAskOrderIds works similar to getAskOrderIds but uses "account" and (optionally) "asset" to filter data.