Summary: This ports the loader to the stable cpp api.
Test Plan: Please test this patch and tell me if there are differences
Reviewers: DaveMDS
Subscribers: jayji
Differential Revision: https://phab.enlightenment.org/D4039
Now configure should abort in case poppler is not found (unless explicitly disabled)
I'm still not sure about the hard "poppler < 0.40" requirement
added by jpeg yesterday, we should fix the issue instead of
tell "we don't support it"