ctest: Allow colored output on Windows if CLICOLOR_FORCE is set to 1
Windows 10 supports ANSI colors since v1511. For earlier versions of Windows installing ANSICON will enable ANSI colors in cmd.exe.
For those setups where the environment is set up with CLICOLOR_FORCE set to 1 ctest should honor the setting and emit colored ANSI output.
Backport: release
Edited by Brad King