DarkThumbs V1.8
Address several issues:
- Issue #76 : make sure the version numbers are consistent
- Issue #78 : fix problems with file sorting ("0.jpg" should be used instead of "1.jpg")
- Issue #79 : Upgrade to the latest RAR code to handle WinRAR5 format.
Also includes a fix for problems handling some image formats (e.g. WEBP) within a RAR/CBR file.