change android:targetSdkVersion to 19(Android 4.4)
Revert "数据库中增加一个字段‘current_semester’，用以判断是否为本学期"

This PARTIALLY reverts commit 82f6b9c61139fef7ea28fcef8fad02814177d636.

Conflicts:
	src/org/orange/studentinformationdatabase/StudentInfDBAdapter.java
Revert "修改下学期课程为更改为本学期的课程显示的问题"

This reverts commit 58fe6518ffbd1d229a8f5e6dc074f33b79025f1c.
This PARTIALLY reverts commit 9898e1027c478950523673134a625f9434cfc9e3.

Conflicts:
	src/org/orange/querysystem/content/InsertDBFragmentActivity.java
	src/org/orange/querysystem/content/NextAllListCoursesActivity.java
	src/org/orange/studentinformationdatabase/StudentInfDBAdapter.java
Revert commit who add updateCurrentSemesterOfAddCourseInf() method

Revert "修改了AddCourseInfActivity.java和StudentInfDBAdapter.java中增加了一个方法用来实现增加的课程的CURRENTSEMESTER字段的值为1，这样就能在本学期项中显示了。"

This reverts commit 40f76b1aaa92e0ee900719a61bfbe0a8909e2977.

Conflicts:
	src/org/orange/querysystem/content/AddCourseInfoActivity.java
	src/org/orange/studentinformationdatabase/StudentInfDBAdapter.java
update parer to get course information from new website

修改 更新解析器，来从新的师生服务网站获取课程信息
修改 更新学期的存储格式
修改 更新本学期和下学期课程的判断方式
修改 由于更新了表模式，旧数据库不再可用，暂时禁用预置数据库功能