Added support for InstallShield v6 cabinets, which can be made up of
multiple files. The interface for creating an Archive instance now takes
the base filename (e.g. the "data" in "data1.cab") for all cabinets,
including single-file ones.
Co-Authored-By: clone2727 <236052+clone2727@users.noreply.github.com>
Co-Authored-By: Walter van Niftrik <615114+waltervn@users.noreply.github.com>