This extension optimizes the SVG file according to the following options:
* Simplify colors: convert all colors to #RRGGBB format.
* Style to xml: convert styles into XML attributes.
* Group collapsing: collapse group elements.
* Enable id stripping: remove all un-referenced ID attributes.
* Embed rasters: embed rasters as base64-encoded data.
* Keep editor data: don't remove Inkscape, Sodipodi or Adobe Illustrator elements and attributes.
* Enable viewboxing: size image to 100%/100% and introduce a viewBox.
* Strip xml prolog: don't output the xml prolog.
* Set precision: set number of significant digits (default: 5).
* Indent: indentation of the output: none, space, tab (default: space).
