cacorrect: clamp the bottom end to zero
(cherry picked from commit 7fd0a2bb0009f20c90356f52b13ca96aec1bdb93)
wb_presets: sony slt-a37 (stolen from ufraw)
(cherry picked from commit e8a7f3f5758e0363f0be7350d5739d4ae5cbdd99)
opencl: don't build cltest without opencl
(cherry picked from commit 8a91e8dabfd960d56c42716765357da94d5e615b)