v1.0
	* ʵģתɴ
	
v1.1
	* װݿConnection
	* CourseManagerʵӿγ̷	
	* õģʽȡCourseManager 
	
V1.2
	* CourseController,ɿγ
	
v1.3
	* ѯγб
	
v1.4
	* ɾγ̺޸Ŀγ̷		
	
v1.5
	* õݹȡ༶Ϣ 	
	
v1.6
	* Ӱ༶
	* عDbUtil	
		
v1.7
	* ɾ༶޸İ༶Ϊҵ
	
v1.8
	* StudentManagerӿ
	* ѧ	
	
v1.9
	* ҵ޸İ༶
		
v2.0
	* ҵݹɾ༶	
	
v2.1
	* ҵҳѯѧ
		