[Bug 1055270] [KK Only][Flame][Camera] Face detection coordinates are in...

...verted
Re-reading these docs, I'm now finding them a little bit misleading.  The locations of the 0 and the X and the conversion stuff is great.

But, as noted up top, the sensor and the screen always line up physically. The pixels recorded at the top of the sensor are the ones that are displayed at the top of the screen.  So having pixels miea at the top of the sensor means that pixels miea have to be displayed at the top of the screen.

To explain this properly, I think we might need three boxes.  One box shows the pixels on the physical sensor.  With miea at the top.  Then another box shows the raw image that the sensor reports to gecko: this image has pixels abcd at the top.  Then the third box shows how gaia rotates that raw image 90 degrees so that pixels miea are at the top again.

Adding to the confusion here is the fact that although these grids of pixels look rectangular, they are actually 4x4 squares. If Mike had made them 6 lines high and four lines wide his rotations would not have worked.

Diego: I'm not suggesting that you modify these docs now. But Mike might want to change them, and if he does, we should change them here, too. Up to you whether you leave them in this state in the PR or remove them for now.