Add DREAMER install notes

From: Ben Keller <bkeller@eecs.berkeley.edu>
To: Jonathan Bachrach <jackbackrack@gmail.com>
Cc: Palmer Dabbelt <palmer.dabbelt@eecs.berkeley.edu>
Subject: Re: forwarded message from Joel Emer
Date: Mon, 20 May 2013 18:39:19 -0700

All,

Below are my notes on the installation process today.  Jonathan, I
don't have permissions to push to the gui repo, so I've attached the
updated Makefile if you want to commit it.

-Ben