ZoomTool doesn't play well with secondary axis

[jonathanrocher]

The ZoomTool doesn't work well with the BroadcasterTool and multiple axis in a Plot. Running the multiaxis_using_Plot.py example, and zooming in a certain range leads to a new plot with the regular axis has the correct range but not the secondary axis.

From the full plot, if I zoom say from (0, 0) to (2, 0.2), the y-axis range should roughly be [-0.05, 0.05]. Instead I get the following:

[jonathanrocher]

cc @rkern @cfarrow @jvkersch .

[jtang-ent]

I had similar problem and found out that I can't share the same value mapper for different y-axis plot in order for zooming to work properly. If you create a container first and then add both plot1 and foreign_plot to the container the zooming should work as expected.