Add parent error messages

lib/errors.js

@@ -138,7 +138,7 @@ util.inherits(error.TimeoutError, error.BaseError);
 error.UniqueConstraintError = function (options) {
 error.UniqueConstraintError = function (options) {
   options = options || {};
   options = options || {};
   options.parent = options.parent || { sql: '' };
   options.parent = options.parent || { sql: '' };
-  options.message = options.message || 'Validation error';
+  options.message = options.message || options.parent.message || 'Validation Error';
   options.errors = options.errors || {};
   options.errors = options.errors || {};
 
 
   error.ValidationError.call(this, options.message, options.errors);
   error.ValidationError.call(this, options.message, options.errors);
@@ -161,7 +161,7 @@ error.ForeignKeyConstraintError = function (options) {
   error.DatabaseError.call(this, options.parent);
   error.DatabaseError.call(this, options.parent);
   this.name = 'SequelizeForeignKeyConstraintError';
   this.name = 'SequelizeForeignKeyConstraintError';
 
 
-  this.message = options.message;
+  this.message = options.message || options.parent.message || 'Database Error';
   this.fields = options.fields;
   this.fields = options.fields;
   this.table = options.table;
   this.table = options.table;
   this.value = options.value;
   this.value = options.value;
@@ -181,7 +181,7 @@ error.ExclusionConstraintError = function (options) {
   error.DatabaseError.call(this, options.parent);
   error.DatabaseError.call(this, options.parent);
   this.name = 'SequelizeExclusionConstraintError';
   this.name = 'SequelizeExclusionConstraintError';
 
 
-  this.message = options.message;
+  this.message = options.message || options.parent.message;
   this.constraint = options.constraint;
   this.constraint = options.constraint;
   this.fields = options.fields;
   this.fields = options.fields;
   this.table = options.table;
   this.table = options.table;