Make ui-sref and $state.href url generation html5mode aware

Hello everyone,

I was using ui-router lately.

I have link like this:
```<a class="btn" ui-sref="campaignManagement.newad">CM</a>```
or like this:
```<a class="btn" ng-href="{{$state.href('admanagement.newad')}}">CM</a>```

Both two generates a link like this:
```<a class="btn" ui-sref="campaignManagement.newad" href="/newad">CM</a>```

The url is ```/newad``` that is true but **I am not using $locationProvider's html5mode** so, when it should be ```#/newad``` written to ```href```

When user clicks to link, their go to /newad which generate 404, but they should go to /#/newad which is the proper state url.

Urls generated by ui-router never includes hashbangs. This is expected behaviour if Hmtl5Mode is enabled. However, if Html5Mode is disabled, than, urls like this /base/path/generated/url generates 404 on page
refresh/direct access. Urls generated should be like

/base/path/#/generated/url/

This commit adds this feature, ```sample/index.html``` updated to show a demonstration about usage.

We can't determine ```Html5Mode``` from ```locationProvider```, because after we read, status may change, so it needs to be explicity set to ui-router.