dt_imageio_open_rawspeed_sraw(): fix off-by-one for monochrome images

This fixes weird fringing on Leica M9 monochrom images
Unbreak non-monochrome sraws

Was broken by previous commit.
vignette: clip inner, unvignetted part of image (fixes #10041)

without this fix the inner area of the image preserves potentially unbounded values
while the vignette area is clipped. unter certain circumstances this leads to
visible artifacts at the transition (see redmine ticket). legacy history stacks
are handled as before. to take advantage of this fix you need to reset the
vignette module.
Hack around a spurious EOF comparison
Comment out an unused constant (clang complains)
Remove some dead code that clang caught
Merge pull request #647 from pedrocr/crw-warning-fix

Hack around a spurious EOF comparison in rawspeed
Merge pull request #648 from pedrocr/fix-clang-warnings

Fix clang warnings in rawspeed code
Histogram: replace dt_iop_roi_t with new dt_histogram_roi_t
Spots IOP: legacy_params(): adapt for latest mask changes
dt_masks_legacy_params(): refactor v1 -> v2 to a function, prepare for v3
Needed preparations for loading of uncropped, unscaled (B/W) raw images
rawprepare: new IOP, no-op (passthrough)
rawprepare: allow tiling

FIXME: verify this!
dt_imageio_open_rawspeed(): break everything! Stop scaling (B/W).
rawprepare: scaling for raw mosaic buffers
rawprepare: scaling for floating point buffers
Deflicker (histogram of: source raw data): fix (no scaling)
Disable "Create HDR": FIXME: this function needs adapting (scaling (B/W))
rawprepare: prepare for using blackLevelSeparate