Added Volume Slider Value and Speaker Value synchronization
- When the volume slider value is changed the speaker value is changed
  accordingly
- When the speaker value is changed in the, the slider is updated based on
  the system volume
Added Volume Slider Value and Speaker Value synchronization

- Declared BpsEventHandler instance in main to get it destroyed with the
  application
Addressed comments from Narek's review
Merge pull request #10 from lkarapetyan/volslider

Added Volume Slider Value and Speaker Value synchronization