SCHEMA-196. Instance format should not use "kiji" protocol namespace.

Change the instance format installed via 'kiji install' to system-1.0,
rather than kiji-1.0. This avoids a namespace collision with layouts, etc.

Support for the original kiji-1.0 format is retained in the interest of
backward compatibility.

Signed-off-by: Milo <milo@wibidata.com>