Returning undefined, will cause any subsequent validation tests to fail

An example of the the issue:

```
 ui-validate="{
	one: false,   // a validation method that would return false
	two: true,    // a validation method that would return true
	three: true   // a validation method that would return true
 }"

```

Validation returns the following:

Before commit: 
- $error.one: false
- $error.two: false
- $error.three: false

After commit: 
- $error.one: false
- $error.two: true
- $error.three: true