Rework the PP5 plugin to actually support multiple face detection

Set detect_base_face_only based on enrollAll (per-file enrollAll is not
supported).
Implement project(templatelist) rather than project(template), when enrollAll
is set, output multiple templates, one for each detected face, with associated
metadata.
Merge branch 'master' of https://github.com/biometrics/openbr into pp5_rework
Merge pull request #55 from biometrics/pp5_rework

Changes to PP5Enroll, proposed fix to #54