CodeEditor: Allow for resizing of editor, terminal, plot sections
It would be great if it was possible to move the borders between the
editor, terminal output, and plot preview section with the mouse cursor
to resize the sections.
Preview plots should resize accordingly with respect to available hight of preview area.
Editor remembers last border positions and automatically uses same sizes next time a file is opened.
(from redmine: issue id 1928, created on 2014-10-16 by Robert.Fischer1, closed on 2015-03-04)