Added more information for the notification `mdm` property.
lint.
Fixed mdm support.
Fixed event emitting in feedback.js
New API to support sending one notification to multiple devices.

One notification object can be sent to multiple devices while only one copy of the notification is kept in memory.
* You should use the new `pushNotification` method to benefit from this. Instead of setting `Notification#device` you instead need to pass an array of device tokens to `pushNotification` as the second parameter.
* The notification object returned by errors has changed structure.
* There is now code to support multiple connections sending notifications but this isn't fully enabled yet, it may work in your environment but hasn't been tested.