fix json
Merge branch 'Bohan-Zheng' into rtong

Conflicts:
	app/controllers/StudyPlanController2.java
comment display function for xiaoran to test
Merge branch 'rtong'
submit button on  student/index

submit button
Merge branch 'master' into rtong
null to []
add null manipulation
Merge remote-tracking branch 'origin/rtong' into bowen
updeate semester page