Add variables for PID and run profile command line arguments

QtCreator supplies Variables that contain data about several aspects of QtCreator and its projects, such as `%{CurrentRun:Executable:FilePath}`.

It would be useful to have (at least) two more, one returning the Command line arguments set for the current project in the Run Settings, and one supplying the PID of the current project if it is already running. The first one is useful in order to be able to start the application via an external tool, while the other is useful to attach an external tool to the running application.