Added TargetPackageName and NotificationKey

Added TargetPackageName (serialized as "restricted_package_name") and NotificationKey (serialized as "notification_key") to the GCM notification object that will be sent to GCM server
Include OldSubscriptionId and SubscriptionExpiryUtc in notification result for expired Windows and Windows Phone subscriptions.
Added FirefoxOS support

- Added PushBroker extensions
- FirefoxOS push channel
- Fluent creation of notifications
Added missing reference for PushSharp.Core
Changed target framework to .NET 4
Remove nasty stuff
Add iOS8 Interactive Notification Support

Add APS "category" property for iOS8 interactive notifications.
Add more category support

Add a fluent helper to set a category and a constructor.
Don't try to convert JObject/JArray to JValue and then to JToken
Apple increased the APNS payload size to 2048
Merge pull request #412 from steveheyman/master

Add iOS8 Interactive Notification Support
Removed specific test for 500 error to comply with Google's documentation:

Errors in the 500-599 range (such as 500 or 503) indicate that there wa an
internal error in the GCM server while trying to process the request, or
that the server is temporarily unavailable (for example, because of
timeouts). Sender must retry later, honoring any Retry-After header
included in the response. Application servers must implement exponential
back-off.

https://developer.android.com/google/gcm/http.html
Added some compatability support for InternalServerError.
Merge pull request #430 from kekekeks/master

Don't try to convert JObject/JArray to JValue and then to JToken
Merge pull request #428 from brianbv/master

GCM - Handing GCM HTTP Errors
Merge pull request #400 from modamoda/master

Typo in Sample project
Merge pull request #399 from Cheesebaron/patch-1

Remove nasty stuff in AppDelegate in sample
Merge pull request #377 from Haythem/mozilla-firefoxos

Added FirefoxOS support
Merge pull request #375 from samcook/expired-windows-subs-fix

Include OldSubscriptionId and SubscriptionExpiryUtc in notification result for expired Windows and Windows Phone subscriptions
Merge pull request #364 from sadra-ab/patch-2

Added TargetPackageName and NotificationKey