提交下本地代码
Merge branch 'type_refactor' of github.com:tddl/tddl into type_refactor

Conflicts:
	tddl-optimizer/src/main/java/com/taobao/tddl/optimizer/core/datatype/IntType.java
	tddl-optimizer/src/main/java/com/taobao/tddl/optimizer/core/datatype/StringType.java