Display of .ppm figures

[goldturtle]

@vanaukenk commented on Jul 7, 2016

Hi,
I am test viewing and annotating WBPaper00041607 and the images are hyperlinked paths like this:
images/C. elegans/WBPaper00041607/WBPaper00041607.tpcas.4.ppm
and don't appear to be displaying.

Alternatively, WBPaper00040565 has a mixture of .jpg and .ppm and it looks like the .jpg files display but the .ppm files do not.