Create a reference plot

[alexjmu]

As per our discussion with Steve, it'd be cool to have a large reference plot for the purpose of zooming in on one part of the data: Selecting a timespan in the reference plot would cause data for just that timespan to be plotted in another graph.

From what I understand, Shiny does not currently support making two independent brush selections on one graph, which means you couldn't use the reference plot to "zoom in" on two different time periods at once for comparison. We might be able to use a couple of sliders to each select a time period instead, but this is obviously less visually pleasing.

Further research is required!

[alexjmu]

Researched Plotly which works with R and Python, and allows interactive graphs. Specifically it seems to have good support for time period selections. Researched Shiny's support for interactive graphs further, which is very small. Could use one large plot to compare components with two smaller plots for selecting time periods.

[alexjmu]

Created a larger, third plot as per be3804f. You can select a period in each of the two smaller plots and see just that data plotted in the larger one. A bit primitive (and needs refactoring!) but good proof of concept.