plotOpts: Plot options
In raredd/iplotr: Interactive plotting functions

In additional to the arguments passed directly to the individual plotting functions, certain aesthetics of each can be changed by using the plotOpts argument. This should be a list of options such as height or width setting the plot size in pixels; rectcolor for the background color of the plot; margin to specify the left, top, right, bottom, and inner margins; or axispos and titlepos to specify the label positions in pixels.

Each type of plot has its own additional aesthetic options:

	`iscatter`	scatter plot (`iscatterOpts`)
	`icorr`	correlation matrix and optional scatterplots (`icorrOpts`)
	`idot`	dot plots (`idotOpts`)
	`itree`	tree plots (`itreeOpts`)
	`icurve`	curves with optional scatterplots (`icurveOpts`)