Feature request: access to raw icc profile

[HappySeaFox]

Hi! 😀

It would be great if jasper gives access to the raw ICC profile if the loaded image has it. Like libjpeg or libpng does. Raw profile = binary data and its length. Like that:

void *icc;
size_t icclen;

jas_image_iccp(image, &icc, &icclen);

It's also discussible if this function should allocate icc, or just return an already existing internal pointer.