icc_import attaches the input profile if used

icc_import can take a fallback input profile in case the embedded one is
broken or missing. If we use the fallback profile, this change attaches
it to the output image.

This means that icc_import will always output an image with the icc
profile that was used to import it. This helps to make the behaviour of
`thumbnail` more consistent.

See https://github.com/jcupitt/libvips/issues/152

improve changelog

oops fix copy-paste error

oops fix copy-paste error

missed another vips-8.5 reference

add "extend" option to affine

so for upsizing with displacement (like resize) we can prevent dark
edges on bright images

see

libvips/php-vips#61

add composite2 to notes

remove "throw" from c++ autogen tools

and output

spelling

fix vips7 py enable flag