Add INSTALL_NAME_DIR

Change-Id: Ic3f00147b384b08d1a231354d4160a3b4d304200
Reviewed-on: http://review.couchbase.org/29144
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>
Tested-by: Trond Norbye <trond.norbye@gmail.com>