提供基于两阶段提交（Try/Confirm/Cancel）的分布式事务实现方案
- JDK6+
- All RPC
- Springframework 3.2+
- 事务预提交
- 事务确认提交
- 事务回滚
- galaxy-demo-purchase：商城系统
- galaxy-demo-repository：库存系统
- galaxy-demo-order：订单系统
- 正常下单：localhost:8080/purchase/rest/{quantity}
- 模拟减库存失败：localhost:8080/purchase/rest/case/1
- 模拟下单失败：localhost:8080/purchase/rest/case/2
- 模拟减库存超时：localhost:8080/purchase/rest/case/3
- 模拟下单超时：localhost:8080/purchase/rest/case/4