Trim whitespace from SVG file

Trim the whitespace from a SVG file by setting the viewBox equal to the bounding box.
Requires ImageMagick installed to obtain the bounding box.

Example:
x = 0:pi/100:2*pi;
figure;subplot(2,1,1);plot(x,sin(x));ylabel('Sine');
subplot(2,1,2);plot(x,cos(x));ylabel('Cosine');
saveas(gcf,'test.svg'); %For instance insert this file into Word, and there is whitespace around the plot.
trimSVGFile('test.svg');
%Now insert this file into Word, and there is no whitespace.