SageCloud, a Boston cloud storage startup, is changing its name and tweaking its business model as it begins shipping its software products to major clients looking for more secure ways to store their business and institutional data. The company is expected to announce this morning that it’s changing its name to Storiant, as a way to better convey its mission to clients, said co-founder and chief executive Jeff Flowers. The name SageCloud suggested to some potential clients that its products…