because MIME strings (those from shared-mime-info package for example)
tend to change and exact MIME string match is unreliable
Signed-off-by: Ivailo Monev <xakepa10@gmail.com>
because it returns only one (definitive) format type using QStringList as
return type makes no sense, also a mode argument is very much required to
return correct result - not all image format plugins support writing
Signed-off-by: Ivailo Monev <xakepa10@gmail.com>
