Changes the render_api to support re-creating the display sub-window and the ability to rotate the displayed framebuffer image. That currently works only when the renderer runs as a thread and not as seperate process. Therefore we setup the library to run the renderer as thread(s) inside the calling process on *all* platforms for now. Change-Id: Ifd009db903759042a7edcf89866d3c3fe076cae9