Doing this via the product condition silently switches the product off
if Qt is too old, which will leave users wondering about the reason.
Instead, use the long-supported version check functionality of the
Depends item, which will result in a clear message in case of a failure.
Also, move the check to QtcProduct. The version requirement is for all
of QtCreator, not just the plugins.
Reviewed-by: Robert Loehning <email@example.com>
Reviewed-by: Jake Petroules <firstname.lastname@example.org>