Revised optimizer and its tests; issue #30

@subutai @scottpurdy please review.
The revisions to optimizer.py are to included bounded optimization.
optimizer_test.py was redone to test against more cases (parameter boundaries, local vs global max) and correct some calculations. I also added detailed failure messages.
Here, and elsewhere, I don't understand the reason for using %r and then a constant. Why not just put in `...max value of  5.0625...`