Extend fpd.getViewsSVG() with the options offered by fabricjs

FPD offers a method called getViewsSVG(). The resulting svg-string contains  width and height,

which is defined by creating the fpd-container.

The underlying fabricjs library offers two parameters, which allow to resize the svg.

Please add those parameters to the getViewsSVG() function or add a new function. It

would enable us e.g. to stretch the resulting svg to the size needed for printing / producing

the 'real product'.