Fix KF1-91 driver texture.
Convert GTV6 indexed png to plain RGB
Convert Algarve 16bit depth png to 8bit and indexed png to plain RGB
Convert Interlagos 16bit depth pngs to 8bit.
Convert Suzuka 16bit png to 8bit.
Convert Parking Lot png to 8bit.
Convert Indian Hill 16bit depth pngs to 8bit and strip unused alpha channel.
Convert Imola 16bit depth png to 8bit.