oozie
Add component : show flow run history.
增加工作流正确性验证：输入输出不能为空，每个节点的required参数不能为空，必须有起始节点，不能有环。
management of hdfs files
Merge branch 'master' of https://github.com/justinliucs/haflow

Conflicts:
	src/main/webapp/script/haflow.main.js
Merge branch 'master' of https://github.com/justinliucs/haflow.git

Conflicts:
	src/main/java/haflow/dto/entity/Flow.java
	src/main/java/haflow/service/FlowService.java
	src/main/java/haflow/ui/controller/FlowController.java
	src/main/java/haflow/ui/controller/HomeController.java
	src/main/java/haflow/ui/helper/FlowHelper.java
	src/main/resources/hibernate.cfg.xml
	src/main/webapp/WEB-INF/views/logon.jsp
	src/main/webapp/WEB-INF/views/main.jsp
	src/main/webapp/style/haflow.main.css