Merge branch 'development' into 'master'

CHANGELOG.md

.../java/nl/tudelft/submit/controller/EditionController.java

...in/java/nl/tudelft/submit/controller/ErrorController.java

...va/nl/tudelft/submit/controller/SubmissionController.java

...submit/dto/view/labracore/SubmitAssignmentSummaryDTO.java

...java/nl/tudelft/submit/security/AuthorizationService.java

src/main/java/nl/tudelft/submit/service/EditionService.java

src/main/java/nl/tudelft/submit/service/GradeService.java

...ain/java/nl/tudelft/submit/service/StatisticsService.java

...ain/java/nl/tudelft/submit/service/SubmissionService.java

src/main/resources/templates/assignment/test_submission.html

...sources/templates/error/disallowed_submission_upload.html

...a/nl/tudelft/submit/controller/EditionControllerTest.java

...l/tudelft/submit/controller/SubmissionControllerTest.java

...st/java/nl/tudelft/submit/service/EditionServiceTest.java

...java/nl/tudelft/submit/service/StatisticsServiceTest.java

...a/nl/tudelft/submit/service/grading/GradeServiceTest.java