OpenEXR: introduce compression controls
Merge branch 'master' of ssh://github.com/darktable-org/darktable
Add legacy_params to libs & imageio ...

... and use it for exr
tiff write_image: rewrite. Use memcpy. Do not overflow
Also set field TIFFTAG_ORIENTATION to ORIENTATION_TOPLEFT.

TIFFTAG_SAMPLESPERPIXEL was set earlier, no reason to set it again.
EXR write_image(): eliminate 3 temp buffers with total size of 3*width*height*sizeof(float)
This is also faster, while image's md5 is still the same (when exif is commented, compression is off and pixel type is float)
EXR: wording changes