Handle stdout & stderr messages more pythonic

Currently (see #191), all output generated by the C++ API is piped to std::cout/std::cerr.

For ideal Python support - which includes pythonic output and logging - one would need to capture the output from C++ and redirect it to message handling facilities in python. This could be Python's stdout/stderr and logging on a very basic level or some advanced implementation that can differentiate and mute multiple levels of output (as present for example in PIConGPU).