80+ columns highlighting messes up rainbow braces and syntax folds

So the corresponding pairs of braces aren't detected properly.

http://www.vim.org/scripts/script.php?script_id=3772

> syntax region cBlock      matchgroup=Operator start="{" end="}" contains=ALLBUT,cCurlyError,@cParenGroup,cErrInParen,cCppParen,cErrInBracket,cCppBracket,cCppString,@Spell fold
