1. reduce iterations
2. add iterations progress indicator
added defensive checks to ensure null pointer exceptions do not occur while putting/deleting documents
add auto-loading for 'all records' page
update testing for ajax-loading
[2580] 'all records' page: make responses auto-load
[2565] NPE in instructorCoursesPage
[2516] NPE from instructorCoursesPage
[2539] Deleting courses causes error
[2546] NPE in InstructorCourseDeleteAction
[2575]stats per institute: reduce loops

fixes #2575
change profile link to all records link
[2595]adminSearchStudent: give a link to the 'all records' of the student

fixes #2595
Merge branch 'master' into Issue2510

Conflicts:
	src/test/java/teammates/test/cases/ui/browsertests/InstructorStudentRecordsPageUiTest.java
	src/test/resources/pages/instructorStudentRecords.html
	src/test/resources/pages/instructorStudentRecordsPageMixedQuestionType.html
	src/test/resources/pages/instructorStudentRecordsPageWithPrivateFeedback.html