Printed special characters render incorrectly on Windows

[TysonRayJones]

The non-ASCII(?) printer.cpp characters here and here do not render correctly on Windows (not in Visual Studio Code, nor in Windows Developer Command Prompt, heh!). This may be due to a MSVC issue. We could fallback (when MSVC is detected) to slightly uglier characters.

Qureg (20 qubit statevector, 1048576 qcomps, 16 MiB):
    -0.0005036+0.0015601i     |0⟩
                Γï«
    0.00019481+0.00023496i    |1048575⟩

We should anyway centralise all such characters into file-top characters (which was the original intention!)