Seeking and Controller API

In the last few weeks I have been improving Aurena, adding support for Seeking and Controller.  This required few changes in the Aurena protocol and some bux fixes. Changes includes:
- Initial seek and precise pause
- Seeking
- Playlist iteration rather then broken random
- Passing local file path to control/next
- API to control the playback
- GTK/Glade UI demonstrating the control API
- AURENA_DEBUG environement to ease debugging
- Many bug and warning fixes