Option to stop images produced by pymc.Matplot.plot being saved?

[PAGWatson]

Hello, currently pymc.Matplot.plot saves the images it produces to disk, resulting in image files appearing in whatever directory the user is in when the plotting commands are run, and it is time consuming to clear them up. Could an option be added to turn off saving of the plots? (Preferably with the default being not to save any, in line with the behaviour in other python modules with plotting functionality - I didn't realise for some time that plots were being saved, so I had to clear up the image files that had appeared all over the place.)