fix "crash on save project"

The crash fix is to always create a new project (done in method ProjectManager::newProject())

Furthermore NewProjectDialog distinguishes now between "create" and "save", since  otherwise it would look ugly on the UI. Imagine these steps:

Open BA, edit something, click "create new project". Now first a dialog for saving is shown, then a dialog for creating. Without the done changes, two dialogs with title "Create project" would show up.