You must now include vips7 support explicitly with
#include <vips/vips7compat.h>
in your code just after including `vips.h`.
The old vips7 names, such as `Rect`, were starting to cause problems
with other packages like opencv.
all the old monitor calibration stuff is gone, we only support sRGB now
im_Lab2disp() etc. have become vips_Lab2sRGB() etc.
compatibility macros keep old code compiling
