Set up subclassing using Object.create

[kuychaco]

This change eliminates having to define and invoke a Surrogate function, makes the source code more readable, and reduces the size of the backbone.js framework.

Object.create sets up the prototype delegation relationship without calling the "parent" constructor function. This is more straight forward than using a Surrogate constructor function just for the sake of setting up subclassing.

[jridgewell]

#3553 😉. Thanks, though!

[kuychaco]

@jridgewell, some thoughts - while similar to #3553, this isn't so much a "duplicate" as it is an alternative approach. With #3553 there were concerns with breaking backwards compatibility. Object.create is vanilla JS (part of the standard JS library since JavaScript 1.8.5), making backwards compatibility a non-issue. Thoughts?

[jridgewell]

Using native Object.create won't work for IE8 or below, which is even more of a breaking change. _.create will fall back to the Surrogate method when needed.

[akre54]

@kuychaco the "backwards compatibility" concerns from #3553 are about people using older versions of Underscore (which didn't have _.create), it's a separate concern from browser support. For what it's worth, Underscore relies on Object.create if it exists.

[kuychaco]

Gotcha, thanks for clarifying!