HubSpot/messenger — pull request #22 by STRML (2013-03-04 19:16:34+00:00)
Title: Fix $.globalMessenger().hookBackboneAjax(). 

Previously it was not accepting options & potentially clobbering options that did exist.

I thought it strange that there was an existence check for Backbone.Ajax, as it is always guaranteed to exist.

I removed the check & tightened up the method somewhat so that it correctly accepts options on individual calls without clobbering options fed to hookBackboneAjax or globally set options.

This enables nice calls like this:

```javascript
this.model.save(data, {
messenger: {
successMessage: "Successfully Updated Model!",
progressMessage: "Updating Model...",
showSuccessWithoutError: true
}
});
```