Optimise SVG

Some SVG files contained other invisible elements (color palettes, menu and guardian logo outside hidden of the viewport of SVG files).

For example the hamburger icon embedded the logo.

![screen shot 2013-08-15 at 18 30 14](https://f.cloud.github.com/assets/85783/970115/69815ab4-05d0-11e3-98d5-36b203cc475d.PNG)


4.5 KB were saved by removing extra elements and re-exporting the problematic svgs.

## Before

Metrics for common/app/assets/stylesheets/global.min.css
    Total rules: 607
    Total selectors: 855
    Average selectors per rule: 1.4
    File size: 141.59 Kb
    GZip size: 38.77 Kb

## After

Metrics for common/app/assets/stylesheets/global.min.css
    Total rules: 607
    Total selectors: 855
    Average selectors per rule: 1.4
    File size: 121.71 Kb
    GZip size: 34.37 Kb

![USA - NSA](http://www.stupidgifs.com/images/full/871.gif)