fix check_in
Merge remote-tracking branch 'origin/rtong' into bowen
Finish CheckInSelectedCourse and CheckAllSimpleAnd Complex interfaces
Merge branch 'rtong' into shuaiwang

Conflicts:
	app/controllers/StudyPlanController.java
	app/controllers/algorithm/req_and_course/TestLinkList.java
asd
add step1 function
Merge branch 'Bohan-Zheng' into rtong
Merge branch 'shuaiwang' into rtong
好了
Merge branch 'Bohan-Zheng' into rtong
delete dead data
updeate semester page
Merge remote-tracking branch 'origin/rtong' into bowen
submit -> submitCourse
auto
Merge branch 'rtong' into shuaiwang
11

11
use session
Merge branch 'bowen' of https://github.com/xixixhalu/sss into bowen
312