Added the ContentType when storing a file with the Amazon S3 storage backend.
Added the ContentType when storing a file with the Amazon S3 storage backend.

nicolaasmatthijs/Hilary,nicolaasmatthijs/Hilary,ExC0d3/Hilary,timdegroote/Hilary,stuartf/Hilary,mrvisser/Hilary,Orodan/Hilary,jfederico/Hilary,timdegroote/Hilary,simong/Hilary,stuartf/Hilary,mrvisser/Hilary,simong/Hilary,ExC0d3/Hilary,Orodan/Hilary,jfederico/Hilary