Doc updates for 1.0.0.Beta1

@agudian Coud you check this out and merge into the 1.0.0.Beta1 branch?

@agudian, @sjaakd: I've also added a contributors section to the development page and took the liberty to link to your Gravatar images (I hope that's ok, let me know if not). If you like, you can add one or two sentences about you there as well.