viewer: read initial image in URL.
viewer: read initial image in URL.

Use a hash like #file=path/to/file&img=INITIAL_IMAGE_ID

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