cleanup: rename objstore -> objectstore

Signed-off-by: Erik Bernoth <erik.bernoth@gmail.com>
Register: collect references and filenames

Signed-off-by: Erik Bernoth <erik.bernoth@gmail.com>
StagingArea: Rename references from Index

Signed-off-by: Erik Bernoth <erik.bernoth@gmail.com>
StagingArea: Enable persistant storage (untested)

Signed-off-by: Erik Bernoth <erik.bernoth@gmail.com>
Record: A better name for "git trees"

Signed-off-by: Erik Bernoth <erik.bernoth@gmail.com>