added Evaluate module as Obj-C interpreter

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
added method headers to archive/unarchive trees

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
renamed objcpp to objc and made driver more like a scripting language driver

Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>