use full word "display" for variable in all places

[ozzloy@gmail.com/oble] / README

prevent the system from sleeping when a user is looking at the screen.

this is accomplished using a camera and opencv to detect a face.

this readme is woefully short.

you'll need to get a file called
haarcascade_frontalface_alt.xml
i was able to get it with this:
  wget http://eclecti.cc/files/2008/03/haarcascade_frontalface_alt.xml

i'm not sure what the rules are on distributing this file, so you'll
have to get it yourself

if you're on ubuntu:
make ubuntu-dependencies
make
make test # assumes you have haarcascade_frontalface_alt.xml in current dir