FYI, here is what they were :
~/CGAL/trunk> file **/*.png | grep -v PNG
BGL/doc_tex/BGL/fig/emst-detail.png: PC bitmap data, Windows 3.x format, 120 x 120 x 24
Convex_hull_3/doc_tex/Convex_hull_3/bunny.png: PC bitmap data, Windows 3.x format, 120 x 120 x 24
Interval_skip_list/doc_tex/Interval_skip_list/query.png: PC bitmap data, Windows 3.x format, 120 x 120 x 24
Jet_fitting_3/doc_tex/Jet_fitting_3/DavidDetail.png: PC bitmap data, Windows 3.x format, 120 x 120 x 24
Kinetic_data_structures/doc_tex/Kinetic_data_structures/kdsDetail.png: PC bitmap data, Windows 3.x format, 120 x 120 x 24
Manual/doc_tex/Miscellany/stopwatch.png: JPEG image data, JFIF standard 1.01
Straight_skeleton_2/doc_tex/Straight_skeleton_2/StraightSkeletonTeaser.png: PC bitmap data, Windows 3.x format, 120 x 120 x 24
Surface_mesh_simplification/doc_tex/Surface_mesh_simplification/fig/detail.png: PC bitmap data, Windows 3.x format, 120 x 120 x 24
iostream/doc_tex/IOstream/io.png: PC bitmap data, Windows 3.x format, 120 x 120 x 24
* .C ---> .cpp
* removed ../examples from paths
* moved some demo/example files out of doc_tex into their respective place
* now it should build properly, again