Re-enable `injectChanges`

### Angular2 appears to work with `injectChanges: true` set in `bs-config.js`

I'm not sure when it started to work, but CSS changes successfully inject into my angular2 app through browser sync.
Note that my app is not in production mode (but that should have little impact for **lite-server**)

I'm only suggesting that `injectChanges` be reverted to it's default value since it's a lot easier to make tweeks without full page refreshes.
Though, I would like to know if there test cases that i could try to see if any limitations still exist
### Environment
- `lite-server` version: 2.1.0
- `nodejs` version: 6.1.0
- `npm` version: 3.8.6
- `angular` version: 2.0.0-beta.12
- OS type/version: Windows 10 x64