SunInfo: switch out SVGs in favor of PNGs.

Older IEs do not support SVG.

Fixes #770.

I got the PNGs from rendering the SVGs at 48x48 in GIMP and exporting.
![sun_pngs](https://cloud.githubusercontent.com/assets/6280000/5145566/8f23f7f6-71ac-11e4-8992-0bf3867faf55.png)