Pixelpipe rework: allow iops to specify from what pipe to compute hustogram
Deflicker: mode switching: gui complete
DEFLICKER_MODE_SOURCEFILE is working?
DEFLICKER_MODE_AUTOMATIC is working?
SSE for uint16_t histogram
Histogram refactoring: v1
histogram v1.5
histogram v1.75
histogram v1.85
histogram v2
histogram v2.1
histogram v2.2