Update backbone.js comment for clarity

Fixed comment in backbone.js
Merge pull request #3326 from biversen21/master

Update backbone.js comment for clarity
Hyphenate compound modifier. 

It's a single adjective: the compound word "two-way" (as opposed to two adjectives: "two" and "way").
Merge pull request #3351 from janaspage/patch-2

Hyphenate compound modifier.
Un-split an infinitive verb tense. 

Just grammar.
Un-split infinitive [v 2].
Merge pull request #3354 from janaspage/patch-3

Un-split an infinitive verb tense.
Update trailing slash for search params.
Merge pull request #3357 from braddunbar/trailing-slash

Update trailing slash for search params.
fixed camel case filename for doc run script
Merge pull request #3360 from morganrallen/localStorageDoc

fixed camel case filename for doc run script
Failing spec for listenToOnce
Fixes listenToOnce memory leak.
test for correct context in event maps
fix listenToOnce with event maps
use on in all cases of listenTo
implement listenToOnce via listenTo
use clearer event names
de-duplicate some of the listenToOnce wrapCallback logic
Return `this` from `#listenTo`