266 mass apply rules

The is a suggested implementation of `setRules` that will let you set validations on an entire object graph from a single definition.

```javascript
var rules = {
	//will apply required, min & max to viewModel.property
	property: {
		required: true,
		min: 10,
		max: 99,
	},
	
	//will apply required to viewModel.property2.childProperty
	property2: {
		childProperty: { required: true }
	},
	
	//will apply email to the elementProperty of each item in
	//viewModel.arrayProperty
	arrayProperty: {
		elementProperty: { email: true }
	}
};

var viewModel = {
	property: ko.observable(),
	property2: {
		childProperty: ko.observable()
	},
	arrayProperty: ko.observableArray([
		{ elementProperty: ko.observable() },
		{ elementProperty: ko.observable() }
	])
};

ko.validation.setRules(target, rules);    
```

Eventually this could be used to pull validation definitions from models, from ASP.NET DataAnnotations, or from any other source.

Any comments/changes/improvements?