Adds setting instance.breakSaveOnErrors (default: true)

When set to false, using .save() will not return on first error.
Instead it will collect all validations and then return an Array of
errors.
Changes error variable names to avoid confusion
Changes setting name from instance.breakSaveOnErrors to instance. returnAllErrors (#96)
Adds type: "validation" to instance.save() validation errors
Changes test to check for `type: "validation"` on validation errors
Merge pull request #101 from dresende/validation-all-errors

Validation all errors