Fixed #731 by adding the page that was removed as part of #719. The issue described in #719 can also be solved by actually setting changed paths in the bnd file for the new project. That is exactly what this commit does. The page validates that you always specify exactly 2 source paths (one for sources, the second for test sources) and if you use path names that are non-default, it will explicitly set those paths in the bnd file.

Feel free to review this, because I'm inexperienced in Eclipse RCP so I might have done some things that are wrong or clumsy. :)