When using control lines for perspective correction, set the number of
vertical and horizontal lines to the proper values instead of
hard-coding them to 4. The minimum line count is set to 2 when using
control lines, and defaults to 4 when using fully-automatic correction.
Resolve minor conflict in ImProcFunctions::transformGeneral and add new
arguments for use of ImProcFunctions::needsTransform in
PerspectiveCorrection::autocompute.
This rotation is different from the Rotate tool and the post-correction
adjustment rotation because it is applied between camera shift and
camera angle. It is equivalent to correcting the camera's roll and is
the same as the rotation calculated by automatic perspective correction.
Comment out parameters that darktable/ART use in case we decide to use
them later. Add yaw and pitch parameters used by the camera-based
perspective correction. Modify homography matrix calculation to use the
camera-based perspective model.
