Maintain stdout and stderr from make

[Chardrazle]

The helper script redirects stderr into stdout, clearly to make it easier for the python parsing component to handle everything in one input. However, this means any development client expecting to parse stderr from 'make' will fail to find anything if the output is sent through colormake. An example of this is Qt Creator, which does actually filter the ANSI escape colours, but relies on errors/warnings being from stderr in order to display them on its 'Issues' tab.

It would be great if this was handled, although I'm aware it would make the python more complicated by having to read both inputs.