opengles emulator: support display rotation and resize

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
6 files changed