Since version 0.5.0 and up doesn't support the old Xpdf header files and because the CairoOutputDev?.h file is not installed on version 0.5.1, I now use Poppler's glib wrapper for PDF loading.
The glib wrapper needs an URI instead of a filename (why?), so the path to the file must be specified as an absolute path to be able to convert it to an URI (file:///dir1/dir2/file.pdf). This also means that the tests files had to be changed to use absolute paths. I added a function (that I'll change to a common utils source) that transform the filename to an absolute path.
