Check for pak0/1.pak in destination folder before copying.
Fix pak0.pak file check bug. Fix install.log bug.
Revert "Check for pak0/1.pak in destination folder before copying."

This reverts commit 5b52bf3262299df78850808108ecd9dfa06f9095.
Add option to re-download all setup files.
Support for re-downloading all setup files.
Add option to remove setup files during uninstallation.