Adds unshuffled_sample which is preferred to sample when shuffling order is not important.

Lots of changes; see README. Tagging now because I forgot to for previous releases.

Changed bb.shuffle to bb.shuffled to reflect the fact that it returns the shuffled list rather than modifying it in place unlike random.shuffle.

Add partial_dependence, plot_partial_dependence_1D, plot_evaluations, and plot_objective.

Adds plot_convergence and plot_history.