Explictly do not support Windows, avoid error codes

[mkaz]

The Windows console does not support the same ANSI character codes, so when they are printed out it ends up looking like gibberish characters.

This PR avoids this by simply returning blank strings for the functions. This removes all color syntax for windows builds only.

Explanation for setting up platform conditional builds is here: https://dave.cheney.net/2013/10/12/how-to-use-conditional-compilation-with-the-go-build-tool

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This change is