#111 add ability for docent to see all portfolio entries

...f/modules/submission/controller/SubmissionController.java

...potsdam/gf/modules/submission/view/SubmissionService.java

...forschen/src/main/webapp/portfolio/js/portfolio-docent.js

...orschen/src/main/webapp/portfolio/js/portfolio-student.js

...schen/src/main/webapp/portfolio/show-portfolio-docent.jsp

...chen/src/main/webapp/portfolio/show-portfolio-student.jsp

gemeinsamforschen/src/main/webapp/taglibs/Menu.jsp

...forschen/src/main/webapp/taglibs/js/unstructuredUpload.js

...amforschen/src/main/webapp/taglibs/js/visibilityButton.js