Feedback wip: can request and return feedback

...end Angular 4/src/app/layout/grupos/grupos.component.html

Frontend Angular 4/src/app/layout/grupos/grupos.component.ts

Frontend Angular 4/src/app/layout/layout-routing.module.ts

Frontend Angular 4/src/app/layout/layout.module.ts

...d Angular 4/src/app/layout/matefun/matefun.component.html

...end Angular 4/src/app/layout/matefun/matefun.component.ts

...ents/destroy-group-modal/destroy-group-modal.component.ts

Frontend Angular 4/src/app/shared/components/index.ts

...uest-feedback-modal/request-feedback-modal.component.html

...equest-feedback-modal/request-feedback-modal.component.ts

...ck-modal/request-group-file-feedback-modal.component.html

...back-modal/request-group-file-feedback-modal.component.ts

...eturn-feedback-modal/return-feedback-modal.component.html

.../return-feedback-modal/return-feedback-modal.component.ts

Frontend Angular 4/src/app/shared/config.ts

Frontend Angular 4/src/app/shared/objects/archivo-types.ts

...end Angular 4/src/app/shared/services/document.service.ts

Frontend Angular 4/src/app/shared/services/file.service.ts

...gular 4/src/app/shared/services/group-document.service.ts

...d Angular 4/src/app/shared/services/group-file.service.ts