Add Hardware-Assisted Simulated Annealing Paper

From: Jonathan Bachrach <jackbackrack@gmail.com>
To: Palmer Dabbelt <palmer.dabbelt@eecs.berkeley.edu>
Subject: hardware assisted layout
Date: Thu, 11 Jul 2013 16:27:36 -0700

here's the parallel simulated annealing paper i was talking about.

  http://ic.ese.upenn.edu/abstracts/hwassistsa_fpga2003.html

  http://ic.ese.upenn.edu/pdf/hwassistsa_fpga2003.pdf