r_OverscanBorders

Changes the size of the overscan borders for the left/right and top/bottom
of the screen for adjusting the title safe area. This is for logo placements
and text printout to account for the TV overscan and is mostly needed for consoles.
If only one value is specified, the overscan borders for left/right and top/bottom
are set simultaneously, but you may also specify different percentages for left/right
and top/bottom.
Usage: r_OverscanBorders [0..25]
       r_OverscanBorders [0..25] [0..25]
Default is 0=off, >0 defines the size of the overscan borders for left/right
or top/bottom as percentages of the whole screen size (e.g. 7.5).