Bug#487530: Doesn't render postscript files any longer

[James Cloos]

The postscript generated by gecko/1.8 is buggy.  Libspectre added a
patch only recently to work around such PS files.

Older versions of evince called gs(1) to render PS; those were not
affected by the incorrect postscript; recent versions use libspectre
(which is a wrapper around libgs).  If your evince uses libspectre you
need a version newer than 0.2.0.  (I only have deb on servers, so cannot
quickly check.)

Cf. http://bugs.freedesktop.org/show_bug.cgi?id=14384