initrd_hooks

Tried to resolve #308 using dmidecode instead of sysfs, which is now
only fallback. But we likely still need to apply some sanity checks on
the resulting lipstats as dmidecode itself is also not unaffected by
faulty hardware.

Also some other small changes. lsusb ist not yet disabled. Still trying
to find a way to gather that information somehow.

Signed-off-by: Lars Beckers <lars.beckers@rwth-aachen.de>