Fix isSubModel caching a negative response for Property.isInstance(<some property>) because mm6Misc.js calls Property.isInstance against a bootstrap Property instance.
Fix isSubModel caching a negative response for Property.isInstance(<some property>) because mm6Misc.js calls Property.isInstance against a bootstrap Property instance.

osric-the-knight/foam,jlhughes/foam,osric-the-knight/foam,foam-framework/foam,mdittmer/foam,osric-the-knight/foam,jlhughes/foam,jlhughes/foam,foam-framework/foam,mdittmer/foam,mdittmer/foam,jacksonic/foam,jacksonic/foam,foam-framework/foam,jlhughes/foam,osric-the-knight/foam,mdittmer/foam,foam-framework/foam,jacksonic/foam,jacksonic/foam,foam-framework/foam