Regression fix: it will happen here.
Masks: refactor constant 1 as dt_masks_version()
Masks: bump version

All new masks (after regression) are fine.
Masks legacy params: base infrastructure implementation
Masks legacy params: handling of images with ORIENTATION_NONE
Masks legacy params: base for handling of images with !ORIENTATION_NONE
Masks legacy params: added if's for each required dt_masks_type_t
Masks legacy params: note about DT_MASKS_CLONE possible types
Masks legacy params: DT_MASKS_PATH: there can be several points in mask
Masks legacy params: DT_MASKS_BRUSH: there can be several points in mask
Masks legacy params: fix DT_MASKS_CIRCLE
Masks legacy params: fix DT_MASKS_ELLIPSE
Masks legacy params: fix DT_MASKS_PATH
Masks legacy params: all deps are fixed. fix DT_MASKS_CLONE (spots iop)
Masks legacy params: fix DT_MASKS_BRUSH
Masks legacy params: fix DT_MASKS_GRADIENTDT_MASKS_BRUSH
Initialize dev->iop before dt_masks_read_forms() call

FIXME: this code smells.
dt_masks_legacy_params: use dev->iop, do not load .so's (dt_iop_load_module_by_so()) manually
Merge pull request #628 from LebedevRI/fix-regression-bump-masks-version

Fix regression, bump masks version