Add --color CLI option to zig fmt

It doesn't actually do terminal color yet because we need to add
cross platform terminal color abstractions. But it toggles between
the single line error reporting and the multiline error reporting.

See #1026
a05acaf9fdAndrew Kelley committed on 5/30/2018, 10:26:09 PMparentd8699ae
4 files changedLine totals unavailable