be more forgiving about x values

buildlut() would fail if rounding moved some of your x values away from
ints
fix vips_hist_match()

it wasn't upcasting input to uint due to a mix-up with VipsHistogram
redo im_fractsurf() as a class
fix cross-phase
redo im_phasecor_fft() a s aclass
more freq_dispatch to deprecated
fix a race in buffer.c
more compact trace output
Merge remote-tracking branch 'origin/7.36' into 7.36
fix some clang warnings
Merge remote-tracking branch 'origin/7.36'

Conflicts:
	ChangeLog
	configure.ac
	libvips/deprecated/im_exr2vips.c
	libvips/foreign/radiance.c
try again on the buffer cache assert
sync
add B_W as a source / target for vips_colourspace()
add GREY16 / RGB16 as colourspace source / target
fix two tiny memleaks
add our valgrind suppressions file
note helgrind usage
stuff
add --uchar option to vips_linear()