Created originally on Bitbucket by Dannephoto (danne)
Continuation of Albert Shihs work: https://bitbucket.org/hudson/magic-lantern/pull-requests/453/white-balance-fix-for-dual-iso/diff
Seems WB_RGGBLevelsMeasured will not work reliably but WB_RGGBLevelsAsShot seems to work also for auto white balance so why not run calculations only from those numbers. Second change would be to run cr2hdr default set to grab WB_RGGBLevelsAsShot instead of as now a command line setting. This PR will need some more polishing and testing but right know it works applying CR2 white balance straight away without any command line adding.