+ * @param encrypt_path will use short hash instead of path
+ * in the mangled name if set to true. Useful for xHTML export
+ * so we do not leak e.g. user names contained in the paths.
+ * Filename itself is stripped if the resulting filename would
+ * become too long (~250 chars).
+ * Prefix counter is not used because
+ * 1) it's hack useful for MikTeX/YAP only
+ * 2) causes many duplicates within the export directory across different
+ * LyX sessions as (unlike in LaTeX export) we use mangled names in
+ * final xHTML export directory.
+ * An example of hashed mangled case:
+ * C:/foo bar/baz.png - > e_95a42ec852ea_baz.png
+ *
+ * It is guaranteed that
+ * - two different filenames have different mangled names (modulo hash collision)
+ * - two FileName instances with the same filename have identical hashed
+ * mangled names.
+ *
+ *