1.delete non-existent css reference in both studentCourseJoinConfirmation.jsp & instructorCourseJoinConfirmation.jsp
2.remove wrong padding style for Confirm and Cancel buttons in instructorCourseJoinConfirmation.jsp
Fix javascript for scrolling
[Fixes #72669418] JavaScript scroll function broken because Anchor.js not included and/or frameBody id removed
Merge branch 'master' into Issue2134
[2134] *joinConfirmation.jsp refers to a *joinConfirmation.css

fixes #2134
1.specify details for extreme cases
2.add two links test
[Fixes #72672494] Clean up StudentEvalResultsPageUiTest
Merge branch 'master' of https://github.com/TEAMMATES/repo into Issue2152