unzip.h/.cpp - unzGoToFirstFile/unzGoToNextFile retrieves information
about the current file, so it is possible to remove redundant calls
to unzGetCurrentFileInfo and speed up general execution.
unzip.h/.cpp are modified accordingly by creation unzGoToFirstFile64
and unzGoToNextFile64 with file info (unz_file_info64) and name as
possible output parameters.
ZipFile::setFilter (it is used to create a file list at ZipFile
constructor) - redundant calls to unzGetCurrentFileInfo64 are removed,
so briefly the time required to generate a zip file list is something
like 1 average old unzLocateFile call.