HTTP Client split

The reason behind the split is that Http\Client class started to grow quite large.

- All listener related methods have been moved in Http\Listener class
- bug fix: Listener:delListener now *really* deletes the listener.
added tests for listener manipulation
Merge branch 'feature/split-httpClient' into develop

HTTP Client split

The reason behind the split is that Http\Client class started to grow quite large.

- All listener related methods have been moved in Http\Listener class
- bug fix: Listener:delListener now *really* deletes the listener.
- added tests for listener manipulation