- Restructure the emit_surface code so that mime types are checked first.

- Add a test parameter to emit_surface to test if the surface will be emitted
  as an image or recording instead checking the surface type as the attached
  mime may override this.

- Mark surface as not clear when mime is attached to avoid optimizing away
  "clear" surfaces that have mime attached.

- Include entire surface in analysis if mime attached (also fixes bug with
  calculating the extents CONTENT_COLOR surfaces)