Use namespace for internal directives to solve issue #29 

AngularStrap has the same directive "throttle" and it causes conflicts, because these functions uses different signature:

and from angular-strap:
```javascript
.constant('throttle', function (func, wait, options) {
```
and from angular-media-player:

```javascript
.factory('throttle', ['$timeout', function ($timeout) {
  return function (delay, no_trailing, callback, debounce_mode) {
```