Log Message:
Update to version 0.38

Changes:

- Security fix for extract_chmLib.  Pathnames containing a ".." element
  will not be extracted.  There doesn't seem to be a legitimate reason
  to use ".." as a path element in a chm file.

  http://secunia.com/advisories/20734/

- Fix for reading some chm files.  Running over a large directory of chm
  files, about 1% of them turned out to be unreadable.  This resulted
  from an incomplete understanding of one of the header fields
  (index_root).  Apparently, this can take negative values other than -1.