WIP - finishing up the vertical alignment of the multi thumb slider. Renaming the generic skins to "HSlider", specific to the horizontal alignment and creating a new vertical alignment skin for each component.
The vertical alignment of the multi-thumb slider is now working.

Had to handle the laying out of the track-highlights separately for each kind of layout.
Changed the way the label editor was implemented in the multi thumb slider. Made it much simpler by using the plain text input component, with no separate "edit" state and an "edit mode" to keep track of when an editing session is in progress. Also removed the keyboard handlers to detect Esc and Enter key presses to finish an editing session.

Changing the label change event on type itself. Earlier, it was being sent only after the focus was moved out of the editor.