tools: enable assorted ESLint error rules

Enables assorted rules from the category of possible errors. These
should not get in the way in any form.

- http://eslint.org/docs/rules/no-control-regex
- http://eslint.org/docs/rules/no-extra-boolean-cast
- http://eslint.org/docs/rules/no-invalid-regexp
- http://eslint.org/docs/rules/no-irregular-whitespace
- http://eslint.org/docs/rules/no-unexpected-multiline

PR-URL: https://github.com/nodejs/node/pull/4864


Reviewed-By: targos - Michaël Zasso <mic.besace@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Roman Klauke <romaaan.git@gmail.com>