API convenience response

Originally posted by Dan Schultz at: https://groups.google.com/a/openhmis.org/forum/#!searchin/openhmis-discuss/Dan$20Schultz$20snapshot/openhmis-discuss/7NoHSbk2F28/rsx1IAsOGQAJ

"have the lower-level endpoints (e.g. /clients, /enrollments) return full "snapshot" objects IN ADDITION to making the historic values accessible at the nested level."