regex by mathias bynes

Properties with dot notation are valid javascript identifiers including reserved keywords. So as an improvement to #1 I replaced the regex with the one here: http://stackoverflow.com/a/9392578/1462065 . That seems to be the most commonly used one.

Would probably be nice to create this regex with this code: https://gist.github.com/mathiasbynens/6334847 and include in the repo to make this easier to update.