tools: disallow multiple spaces except indentation

Except for indentation, disallow multiple whitespace around logical
expressions, conditional expressions, declarations, array elements,
object properties, sequences and function parameters.

PR-URL: https://github.com/nodejs/node/pull/6645
Reviewed-By: Michaël Zasso <mic.besace@gmail.com>
Reviewed-By: Brian White <mscdex@mscdex.net>
Reviewed-By: Roman Reiss <me@silverwind.io>

.eslintrc

@@ -30,6 +30,7 @@ rules:
   # Best Practices
   # http://eslint.org/docs/rules/#best-practices
   no-fallthrough: 2
+  no-multi-spaces: 2
   no-octal: 2
   no-redeclare: 2
   no-self-assign: 2