Improving comments, headers and function names.
Improving comments, headers and function names.

Using retrieved array (instead of difference of other arrays) for quantity in header to make sure calculation is correct.

NicWayand/OpenSfM,mapillary/OpenSfM,edgarriba/OpenSfM,NicWayand/OpenSfM,mapillary/OpenSfM,mapillary/OpenSfM,sunbingfengPI/OpenSFM_Test,NicWayand/OpenSfM,edgarriba/OpenSfM,NicWayand/OpenSfM,mapillary/OpenSfM,sunbingfengPI/OpenSFM_Test,oscarlorentzon/OpenSfM,onecue/OpenSfM,oscarlorentzon/OpenSfM,oscarlorentzon/OpenSfM,onecue/OpenSfM,mapillary/OpenSfM,edgarriba/OpenSfM,BrookRoberts/OpenSfM,onecue/OpenSfM,sunbingfengPI/OpenSFM_Test,edgarriba/OpenSfM,BrookRoberts/OpenSfM,oscarlorentzon/OpenSfM,NicWayand/OpenSfM,onecue/OpenSfM,BrookRoberts/OpenSfM,onecue/OpenSfM,oscarlorentzon/OpenSfM,sunbingfengPI/OpenSFM_Test,sunbingfengPI/OpenSFM_Test,BrookRoberts/OpenSfM,BrookRoberts/OpenSfM,edgarriba/OpenSfM