make nearest_power_of_two public function

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
add iom_nearest_power_of_two test

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
dont allow zero ringbuffer

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>
ignore core files

Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net>