Multiple figures in one cell flips order of images

[jpauwels]

e.g. when typing figure; plot(ones(1,5)); figure; plot(zeros(1,5)); in a single cell, the output shows the second graph first.

[kb1ooo]

This is because it writes the plots to disk from the matlab engine, then reads the plots from python. The order the files are read are by filename, not by modify/create time. See #134