Based on the discussion on the git list, here are some important changes
to the glossary. (There is no cache, but an index. Use "object name"
rather than "SHA1". Reorder. Clarify.)
Signed-off-by: Johannes Schindelin <Johannes.Schindelin@gmx.de> Signed-off-by: Junio C Hamano <junkio@cox.net>