Fixed grep and awk commands.

I noticed that due to differences between wat the grep and awk commands were assuming, and what the actual output from app/console was, the autocomplete didn't complete anything. This change fixes that.

I don't know if it's environment specific. This fix worked for me in a Vagrant box with Ubuntu 14.04, php 5.5.13, and a Symfony install that identifies itself as 2.7.0-DEV.