Fixes issue with verbose symbols not printing correctly on windows.

When running verbose console mode in windows, 'Heavy' check marks and multiplication signs don't print on the console.
https://github.com/visionmedia/mocha/commit/1eec8be4d0618feb9dca03a28f06ba3af1254f66
https://github.com/visionmedia/mocha/pull/641

Here is a fix for lab.
Sets default terse/verbose symbols
Overrides them for windows.