+- improve recognizer: two passes for polygons (low tolerance, then higher)
+ to better detect elongated rectangles? (if low tolerance recognizer
+ doesn't get a rectangle, then use higher tolerance for everything else,
+ since otherwise there's too much risk of splitting a segment into 2)
+- snap-to-grid (also for ruler & recognizer vertices)
+ and maybe also snap-to-vertices (option for ruler and recognizer)?
+- allow broken PDF with some 19-byte xref entries (LF instead of CRLF).??
+ (Phil Rhoades 3/25/08)
+