fixes #728
* updated API spec to inculde futuers trade and price examples
#727: Introduce UserTrade
#727: add fees to HitBTC and VaultOfSatoshi user transaction history
#727: introduce and use UserTrades
#727: Use and test UserTrade(s) in tests
Fixed bug in adaptOrderType()

"buy" is not the server response.  It should be "bid".  Otherwise this method always returns OrderType.ASK
Changing trade.streaming.BTCChinaBalance.toString() method to be prettier.

Before, the method printed out a nasty string that prefixed the entire package name like:
com.xeiam.xchange...streaming.BTCChinaBalance@7f374, which is not a useful string.  The method is
now changed to behave like the toString() method in BTCChinaOrder of the same package.
Changing trade.streaming.BTCChinaBalance.toString() method to be prettier.

Before, the method printed out a nasty string that prefixed the entire package name like:
com.xeiam.xchange...streaming.BTCChinaBalance@7f374, which is not a useful string.  The method is
now changed to behave like the toString() method in BTCChinaOrder of the same package.
Merge branch 'toStringRequest' of https://github.com/bryan4887/XChange into toStringRequest

Conflicts:
	xchange-btcchina/src/main/java/com/xeiam/xchange/btcchina/dto/trade/streaming/BTCChinaBalance.java
fixes #728
Merge pull request #736 from bryan4887/bugfix

Fixed bug in BTCChinaAdapters.adaptOrderType()
Merge pull request #737 from bryan4887/toStringRequest

To string request
Remove default timestamp from LimitOrder.Builder
Merge pull request #738 from rafalkrupinski/fix/limit-order-builder-ctor

Remove default timestamp from LimitOrder.Builder
Merge pull request #728 from douggie/develop

OKCoin Futures Price Data & Trading Support
Merge pull request #734 from timmolter/trade-subclass

Trade subclass
fixes #728
Use Use_Intl=True if using futures AIP
Merge pull request #739 from douggie/develop

fixes #728 Use Use_Intl=True if using futures AIP