Test much more strict

This tests the return value of each and every procedure call.

Signed-off-by: Frank Terbeck <ft@bewatermyfriend.org>
baudrate.t: Add prefix to module symbols

Next step: Add baudrate tests for the with-exceptions module.

Signed-off-by: Frank Terbeck <ft@bewatermyfriend.org>
Add missing module import

Signed-off-by: Frank Terbeck <ft@bewatermyfriend.org>
baudrate.t: Test the with-exception module as well

Signed-off-by: Frank Terbeck <ft@bewatermyfriend.org>