Fix parsing of ISO Date from being totally lenient to being semi-strict
by requiring the separator positions to be non-numeric.
[ChangeLog][Important Behavior Changes] Parsing of Qt::ISODate by
QDate::fromString() and QDateTime()::fromString() is not as lenient as
before, the date component separators are now required to be
non-numeric. This means a string like "2000901901" will no longer be
recognized as a valid ISO Date, but "2000/01/01" will still be even
though it doesn't strictly meet the ISO format of "2000-01-01".
Task-number: QTBUG-34141
Change-Id: I0e481144136c60d4cac61364b9b2c1d2cd1e78fc
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
684ebc6648