NPM/Browserify support

Please also publish the new versions on NPM via `npm publish`.

This should also resolve https://github.com/angular-translate/angular-translate/issues/255
add
```
"homepage": "http://angular-translate.github.io",
 "bugs": {
  "url": "https://github.com/angular-translate/angular-translate/issues"
},
  "keywords": [
  "i18n",
  "angular",
  "translations",
  "interpolation",
  "international"
],
```