New issue 931: Make `annotate_title` the standard method for setting the title in PhasePlot objects https://bitbucket.org/yt_analysis/yt/issue/931/make-annotate_title-the-stand...

Cameron Hummels:

Right now, `PhasePlot` and `PlotWindow` classes have separate methods for setting the figure title, `set_title()` and `annotate_title()` respectively. To reduce confusion, it might make sense to combine these to be just one of the two options.