contrib/coccinelle: add basic Coccinelle transforms
Coccinelle (http://coccinelle.lip6.fr/) is a program which performs
mechanical transformations on C programs using semantic patches. These
semantic patches can be used to implement automatic refactoring and
maintenance tasks.
Add a set of basic semantic patches to convert common patterns related
to the struct object_id transformation, as well as a README.
Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>