Implement shared counts data

[Shians]

Issue

Currently each MD plot carries its own instance of the counts matrix, this is very expensive when multiple contrasts each have their own MD plot.

Implementation details

• Data is passed into HTML page via execution of .js file. Direct reading of local json is not allowed so a js is required to declare/inject the data.
• Each HTML has its own .js file in order for them to share a folder without clobbering each other's data. The html name and its associated js filename is declared in the glMDPlot(html=) option.

Possible solution

• Produce a single html that can be toggled between contrasts.
• Produce a separate JS file for counts and remaining information, add argument in R to declare a shared count file.