OK, I figured out it was completely unnecessary to install GEF 3.4.1 examples, Tersus actually cares about GEF during installation. Tersus documentation really needs to be cleaned up. However, my problem was another plugin which requires higher version of the draw2D library, and it was solved by manually installing higher version of the draw2D library under plugins after Tersus was installed. You can find draw2D as archived release at the bottom of this page http://www.eclipse.org/gef/downloads/
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