Add code to remove background rect from print

The background rect object that was found in the SVG formatted files was
there given the fact that Emperor allows you to set the background color
for the print. If we leave this object in there we cannot use Inkscape's
fit to drawing area functionality.
Change inkscape command call to crop the prints

Prints are now cropped to be the size of the area these are using only.
Merge pull request #10 from ElDeveloper/print_cropping

Print cropping