Render to Frame Buffer Object.

Render to Frame Buffer Object.

* A new feature has been added to dali-core/dali-adaptor to
  measure the performance above 60 fps avoiding the vsync.

  It renders the frames into a Frame Buffer Object. However,
  is possible to render into the default Frame Buffer every
  certain number of frames.

* Usage: $ DALI_FPS_TRACKING=1 DALI_RENDER_TO_FBO=30 path_to_DALi_app

  Will render into the Frame Buffer Object 29 frames of 30, the 30th
  will be rendered into the Frame Buffer. Will show as well the FPS.

Change-Id: I37b3ae6efaf9e618f9cf34583c75db4187327044
Signed-off-by: Victor Cebollada <v.cebollada@samsung.com>