archives: avoid collapsing archive with single folder

We have historically used the m_bIsFolder after this as a flag,
to skip display of file. For example for rar 00X part files.

By not collopsing single folders, we can properly browse into
them again.
Properly handle cookies that specify a sub-domain
ffmpeg: correctly handle cookies that specify a sub-domain
Merge pull request #4081 from voguemaster/master

ffmpeg: Correctly handle cookies that specify a sub-domain.
Merge pull request #4050 from elupus/archivefolder

archives: avoid collapsing archive with single folder