Fixed error in trim() of notification
Fixed notificationWaitingTimer handling issue.
Added Connection#countNotification and Connection#hasNotification.
lint.
Updated README
Merge branch 'master' of https://github.com/michaelvillar/node-apn into develop
Now Connection#transmissionError and errorCallback receieve deviceToken.
Changed event name `bucketAvailable` to `ready`.
Improved `Feedback` performance, modified some API.

- Inherited `EventEmitter` object.
- Added some events.
- device token in `feedback` and `batchFeedback` events is a string instead of `Device` object. In this way it uses less CPU and memory.
- Removed `options.feedback` and `options.errorCallback`.
Removed options.errorCallback from Connect object options.

And updated README.
Removed options.batchFeedback and related function.

It is not library's task but client's.
With events found in the current implementation, client can very same
thing by it's own hand.
Added `options.tokenType` to `Feedback` service options.

A string value, either "string" or "binary". Specifies type of the
`device token` argument of the `feedback` event.

If it is "string", `device token` will be a hex string.
If it is "binary", `device token` will be a `Buffer` object.
Updated README and modify method comment of `Connection.connect`.