CopyeditForm: fail if project has integrity errors.

If a project has been submitted and is in "awaiting copyedit" stage,
and the project contains integrity errors (either because there are
errors that weren't caught at submission time, or because the editor
changed something that causes an error), then the editor should be
required to fix those errors before the project can be advanced to
"awaiting author approval".

physionet-django/console/forms.py

@@ -281,6 +281,9 @@ def __init__(self, *args, **kwargs):
     def clean(self):
         if self.errors:
             return
+        project = self.instance.project
+        if not project.check_integrity():
+            raise forms.ValidationError(project.integrity_errors)
         if self.cleaned_data['made_changes'] and not self.cleaned_data['changelog_summary']:
             raise forms.ValidationError('Describe the changes you made.')
         if not self.cleaned_data['made_changes'] and self.cleaned_data['changelog_summary']: