Fixed criterion name with label which is displayed to the user.
TNL-768
Merge pull request #631 from edx/waheed/tnl768-fix-criterion-name

Fixed criterion name with label which is displayed to the user.
Fix field AssessmentPart.criterion to point to Criterion table.

Migration 0020 incorrectly altered the field to point to the
CriterionOption table.

TNL-826
Catch and log DatabaseErrors in assessment.api.self.create_assessment.

TNL-812
Added test for DatabaseError in assessment.api.self.create_assessment.

TNL-812
Merge pull request #635 from edx/usman/tnl812-catch-db-errors-in-api

Catch and log DatabaseErrors in assessment.api.self.create_assessment.
More accurate validation for date & time in studio editor.

TNL-58
Added email address to AUTHORS.
Using ISO_8601 for date formatting instead of string.

TNL-58
fixed the multi-line issue for criterion prompt, criterion option text,
peer assessment feedback and self assessment feedback.

TNL-814
Comment refactoring.

TNL-58
Adding more readable comments to catch block.

TNL-58
Merge pull request #638 from edx/muzaffar/tnl58-date-validations

More accurate validation for date & time in studio editor.
TNL-62, TNL-72 and TNL-811
Merge pull request #633 from edx/ammar/tnl72

TNL-72 & TNL-62 & TNL-811
Merge pull request #634 from edx/usman/tnl826-assessment-part-criterion-foreign-key

Fix field AssessmentPart.criterion to point to Criterion table.
Code refactoring after PR code review.

TNL-814
Merging master into this branch
Code refactoring after PR code review.

TNL-814
Minor code refactoring.

TNL-814