Horizontal scrolling view with navigation handles


Itembox view for list and smartlist now have ability to have to dispay all columns with desired width by introducing horizontal scrolling mode. In this mode itembox content can be scrolled horizontally.
The column that contain link to the item and columns that are left to it appear in so-called 'frozen area' and are always visible, to allow easy navigation to content. Action columns are also always visible.
Also added  buttons for easy scrolling itembox content horizontally when the number of rows is big and content is scrolled vertically. Those buttons are always visible when content need to be scrolled horizontally an perfrom horizontal scroll to next itembox column.
Horizontal scroll is also available for grouped view and tree view display modes.
Application option is added to enable or disable horizontall scroll mode for itembox.