Conflicts:
	cat-home/src/main/java/com/dianping/cat/system/page/abtest/Payload.java

 two abtest pages finished. 

revise the JettyServer

DefaultABTestContextManager添加getContexts()方法，返回当前所有context，后续给Cat.logMet...

ABTest Home initial commit

Refactor the code

ABTest Demo Initial

与克祝的从xml读取model信息整合并修改了merge conflict。

RoundRobin ABTest Group Strategy demo

完成从abtest.xml读取entity，初始化DefaultABTestEntityManager; 完成DefaultABTestEntityManager的UT

define data model

integrate group strategy into context manager