Moved the scrollbars inside TrackContainer, enabled Zoom functionalities, various changes in the Track*, *TrackView and SampleView classes to be better delineated the competences. Updated mute and close icons. Enabled experimental features in VolumeSlider. Enabled the vertical scrollbar, and initial implementation of the horizontal scrollbar. Other minor fixes, codestyle and cleanup.
Added FaberScrollView implementation and TimeTrack header.