cfg: group dead code and executed data in blocks

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
README: adds description of analyses

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
program: fix missing file close!

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>