Changing splash logo

Responding to issue raised by Julien.

![screenshot 2014-12-05 12 08 05](https://cloud.githubusercontent.com/assets/29096/5319445/6bac17a6-7c77-11e4-891d-636da19077be.png)

The new SVG has the space below the baseline for descender characters. This space is common to all element style logos in the family. "Format.JS" has no descenders. The previous SVG image did not have this space, so it pushed the tagline down. This compensates for that, restoring the space between the logo and the tagline as before.