add presentation of today

Signed-off-by: Nico Schottelius <nico@freiheit.schottelius.org>
add new presentations from linux erfa

Signed-off-by: Nico Schottelius <nico@freiheit.schottelius.org>
+discussions

Signed-off-by: Nico Schottelius <nico@freiheit.schottelius.org>
steven is right

Signed-off-by: Nico Schottelius <nico@freiheit.schottelius.org>
support for centos

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>
add centos support to __postfix* types

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>
ensure file exists

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>
support for centos

Signed-off-by: Steven Armstrong <steven@icarus.ethz.ch>