Use proper terminal description rather than sys.platform to determine ANSI code support

[aomader]

Currently, the win32 wrapper for stdout and stderr is installed when the python interpreter runs on a Windows machine. But, this check isn't appropriate to determine whether the terminal supports the ANSI codes. This leads to the effect, that if you use Python inside a proper ANSI terminal on windows, e.g., an MSYS environment, the output is incorrect, because all ANSI codes are stripped.

The above mentioned check should instead determine, if the current terminal supports ANSI codes.