#354 Support for all axes in right-click popup-menu

[Anonymous]

The right click popup menu we get when right-clicking on a plot area should support all axes of the plot (properties -> plot), not just the primary X and Y axes. It probably makes sense ot make the popup resizable, in case there are many axes and the tabs of the TabbedPane will need more than one row on the screen.
I think this feature can be implemented easily enough by anyone knowing where the right-click menu is generated by adding a loop to the generation of the axis tab.