Lineplot (rebased onto develop)



This is the same as gh-2625 but rebased onto develop.

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Line plot in Graph pane. The graph is using the points composing the lines
To avoid confusion. I have rename pixels to name
and add location of the points in pixels and microns see https://trac.openmicroscopy.org.uk/ome/ticket/12247

To test 
* Draw a line
* Go to the graph pane
* Mouse over the line. The location should be displayed in the tooltip.