Fixed some xss stuff with sticky answers for students.
Merge branch 'release/2.7' of https://github.com/openwebwork/webwork2 into newxssfix

Conflicts:
	lib/WeBWorK/ContentGenerator/Problem.pm
Made new xss stuff work with gatewya quizzes
Merge pull request #47 from goehle/newxssfix

Newxssfix