add get_preloader_dict method to cases to support 1.3 style preloaders
add get_preloader_dict method to cases to support 1.3 style preloaders

puttarajubr/commcare-hq,qedsoftware/commcare-hq,puttarajubr/commcare-hq,qedsoftware/commcare-hq,puttarajubr/commcare-hq,puttarajubr/commcare-hq,SEL-Columbia/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,dimagi/commcare-hq,SEL-Columbia/commcare-hq,dimagi/commcare-hq,qedsoftware/commcare-hq,SEL-Columbia/commcare-hq,qedsoftware/commcare-hq