Added uiInclude directive in module ui.include.

Directive was proposed here: angular/angular.js#3151 and should resolve issue: angular/angular.js#946.

Usage:

```html
<ui-include src="'my/url/to/partial/file'" fragment="'#id-to-fragment'"></ui-include>
```

The fragment and src attributes are Angular expressions. When fragment is specified, it uses angular.element().find(), and therefore requires jQuery if full selectors are desired, otherwise falls back to Angular's jqLite (which can only find by element name).