Scrollbar
=========

   If you create very large expressions they might not be fully shown
in the  Editing Area, so methods to scroll the window is needed. One
possibility is to move cursor to the edge of the window and beyond,
which will cause the window to scroll. When reviewing an entered
expression it can be easier to use the vertical and horisontal
scrollbars for fast scrolling around the expression and that is
basically what they are for.

   Note: For some reason the editing area flickers when using arrow
bars, but not when using keymovement - I need to find out why as it
isn't exactly pretty.