Use good m_ functions, because it smell like a flower, version 2.

Use good m_ functions, because it smell like a flower, version 2.

This is a whole bunch of update for using more m_* functions.
Some calculation should be checked, maybe I made some mistakes.
Not good at math.

There is also some _CHECKED__ comments removed because I got
my head checked by a jumbot jet.

Signed-off-by: Julien Danjou <julien@danjou.info>
Signed-off-by: Pierre Habouzit <madcoder@debian.org>