Added the ability to correctly create a TestLogger when not
using the standard library. This was done by creating a constant
TestLogger and a set_logger function that returned a constant pointer
to the constant logger.
While external loggers can be used, if you are compiling with
--features use_std, then it will default to just printing everything
to the stdout unless a logger is created.
This library can be used without the STD library, however, you will have
to write an external logger.
