Update to version 6.0.0

Changelog:

• Faster disk scanning on Windows and Unix and on OS/2 with Watcom C built version. This was achieved by removing the DOSDIR directory interface layer and replacing it with system specific functions. Disk scanning speed depends on external factors, like disk caching and other processes accessing the disk at the same time. The speed increasement you experience may vary.
• Fixed -rmtree for unicode file names on Windows.
• Support EMX symbolic links on OS/2.
• Support bash on OS/2.
• New Danish translation of the messages. Thanks to Joe Hansen.