Corona Simple config.lua supporting multiple devices

config.lua

--http://forums.coronalabs.com/topic/37362-improvement-to-the-ultimate-configlua-file/
--The effect of that bit of math is to set the content width or height appropriately for letterbox scaling according to the aspect ratio of the device.  Why is that good?  Because the upper-left corner is now (0,0), and display.contentWidth and display.contentHeight now cover the entire screen.  For example, on an iPhone 5, display.pixelHeight is 1136 and display.pixelHeight is 640.  If you do the math, you'll see that it'll set width to 320 and height to 568. 
-- It'll set the width and height appropriately for every single device, no matter what the resolution or aspect ratio.  And there's no need to code into your config.lua different blocks for different devices.
--the upper-left corner isn't at (0,0).  Instead, it's at (display.screenOriginX, display.screenOriginY)

local aspectRatio = display.pixelHeight/display.pixelWidth
 
application = 
{
    content = 
    { 
        width = aspectRatio>1.5 and 320 or 480/aspectRatio,
        height = aspectRatio<1.5 and 480 or 320*aspectRatio,
        scale = "letterbox",
 
        fps = 60,
 
        imageSuffix =
        {
            ["@2x"] = 1.5,
            ["@4x"] = 3.0,
        },
    },
}