Updated LAV Filters to 0.59.1-5-f74c5c2 (custom build based on stable version 0.59.1).
Update Changelog.txt
Get rid of comma in delete statements.
Be consistent with NVIDIA name.
Installer: Use Inno Setup Preprocessor's `AddBackslash` function.

Also bump the required Inno Setup version in VSFilter's installer.
build.bat: Add error checking when extracting the DX cab files.

Also allow `EXPAND` to show info when doing its job.
Indentation improvements and trim trailing spaces from comments.
No need to nullify a member variable in a destructor.