Move startup pointer [fixes #29]

I've moved the startup message, and modified the text a little (so it doesn't refer to the add-ons bar).

We might want to delay merging this until Australis is released, otherwise it might confuse a few people.

Shown in the current version of Firefox (so with no Australis):
![Picture!](https://f.cloud.github.com/assets/755354/2428312/2b9e5c4e-ac40-11e3-88f7-900b4162878b.png)