Breaking Changes
The upgrade from V8 4.1 to 4.2 will require a recompile of all native add-ons. (The API surface area has not changed significantly, so most add-ons will "just work" after a recompile.)
Parsed URL objects returned by the url module no longer have own data properties, but instead accessor properties on their prototype. This means that e.g. parsedUrl.hasOwnProperty("href") will now return false, and common object-copying methods (like Underscore/Lo-Dash's _.extend or ES2015's Object.assign) will not copy over the URL properties.
To get back an object with the appropriate own data properties, use parsedUrl.toJSON().
