Move background material into background section

As Wayne mentioned, much of the historical information is valuable but not part of the project scope. I moved most of the verbiage to the background information section and left the scope section short and precise. The project scope is really the one part of the proposal that lives on after the project is created, so it is worth crafting clearly.

Another possible item to include in the scope is whether the project intends to maintain a repository of vert.x modules, or provide software to support managing and interacting with such a repository.

Also is running on non-JVM-based servers such as node.js definitely out of scope or is it possible down the road? If unsure there's no need to mention it now.