Doesn't took much time. Even nothing happend.
PyLong_AsLong trys to convert to int bevor raising an Exception.
 
I'm not sure if struct.pack('l', x) should raise an Exception when a
float is given. In case of string there is one.

I first did PyLong_Check the parameter and raised an StructError. But I
removed this from the patch.

I leaved the documentation untouched. Nobody will notice the changes.

I increased the version number. Whether we overwork the Errors prior
3.1b or not we could leave it at 0.3.