Improving journey documentation.
Improving journey documentation.

Correcting journey constructor documentation and adding journey wrapper documentation.

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