Example brightness

TODO: {{#todo:InProgress(11.13.13-13:48->JG+)|Jgreene|oe 4,oe 5,jg,md,InProgress}}

This procedure provides an overview of how to compile and run the brightness C example project. It assumes familiarity with the C programming language and is intended to be used by experienced programmers who are looking to learn the EMAC SDK.

What it does

From the comments in brightness.c

   Simple Brightness/Backlight control for the EMAC PPC-E7
   and SoM-9307. Implements a slider application in GTK+
   that directly controls the backlight through its sysfs
   interface. Tested under Xfbdev/Matchbox.