Implementation of the simulated annealing algorithm
including two demos.

Tested on system with:
* Python 2.4
* NetworkX
* Enthought packs (numpy, scipy)
* IPython Shell

To solve your own problem, all you need to do, in principle
* create a new "design" class which specifies the problem
* create a new cost function
Notice that you can have the cost function run with certain parameter values
by passing those parameters to through a subdictionary of the
dictionary you pass to the sim. annealing algorithm (key="costParams").