breaking tests for assns w/ foreignKey fields

when specifying an associaiton that has a foreign key in which the attribute name and field name are different
certain helper methods do not work because they fail to substitute the attribute name with the field name in the
query, this includes set[AS] and remove[AS]
Merge branch 'error-association-fields' of https://github.com/vpontis/sequelize into vpontis-error-association-fields
fix(model): model#destroy now supports field, this also fixes an issue with N:M#removeAssociation and field
Merge branch 'vpontis-error-association-fields'