Enums are stored as strings, that improves configuration file
readability and maintainability. String values are obtained via
QMetaEnum, and since with Qt 5.5 QMetaEnum::fromType() includes a
static_assert, this has to be a safe method.
moc from Qt4 ignores Q_ENUMS when it is behind #if QT_VERSION check.
Therefore moc entries for enum in TorrentFileGuard were not generated
and the setting was not saving/loading. This closes#6103, #5451
Some browsers do not download files, intended for immediate opening,
into a temporary directory, and thus a regular download directories
accumulate those unneeded files.
The option allows qBittorrent to clean after itself and delete those
files whether they were succesfully added or not (user-selectable
policy).
Eugene Shalygin