- solidify/povray.c (povray_face), solidify/project.c (read_face_data): x
inclination of the z0 plane was reversed in POV-Ray output and in the
project file
- solidify/project.h (struct project), solidify/project.c (make_project,
load_project, save_project): allow project descriptions to begin with
any numer of comment lines and preserve them across sessions
- solidify/overlap.c (merge_matrix): don't shrink the offset vector
- solidify/project.c (read_face_data): the value to assign to f->z_ref
needs rounding or truncation will go wrong from time to time
