A Spatial* object or list of Spatial* objects such as those
generated by canvec.load()
options
A list object with the graphical options to be applied
to the layers specified
crs
A CRS (as generated by sp::CRS()) in which to project the data.
add
TRUE if layer or layers should be added to the current plot, FALSE
if all layers should be plotted on a fresh plot (not reccomended) or NULL for
default behaviour, which will create a new plot for the first layer and add
each subsequent layer