Split to Avoid out of Memory in Higher Resolution

In order to avoid the run out of memory of the GPU when render at high resolution it will be very useful to have an option to flag "split image" so the render is split in four stripe, calculated one after other and at the end atomatically resembled ad saved as one image. This basic technique is used by many renderfarm and in Vantage it will be very useful because GPU at the moment has 24Gb max and when render a Hi Res (8k and over) it is very common to run out of memory obtainig many textures errors in the images.