GSoC - Push Notify test examples.

To show a simple usage of push notifications I developed 2 test examples.
I really want to thank FPComplete for giving me the possibility of hosting the Yesod app.
The tests are available online on [1] and the code is available on GitHub [3].

* BackAndForth Messaging:
In this example, I show how to use the push-general library to handle the registration/reception and sending of messages. From a Yesod app, you can send notifications to devices registered and receive messages from them.
When the server needs to send a message, uses the general api for sending a notification and handling the result in order to correctly actualize the DB. This means removing the devices that have been unregistered and changing the regId of the devices that have changed.
To try this example:
+ On an Android device, you follow these steps: [2].
+ On a WindowsPhone device, you can download the app from Microsoft Store: [4]
+ Once you registered on Server, you can start sending/receiving notifications through the website: [1].

* Connect 4:
I have been thinking of an app which lets me show how useful push notifications are. The advantage of this notifications is that you can receive information from server when it is available without needing to continually poll. So, I started to think about a multiplayers game. Every time a player does something, you let the rest know about the new movement. So, I ran into the board game: "Connect 4".
Both, authenticated web players and users of the android app, can play one against each other.
For actualizing the website, I use long polling, while for the Android app, push notifications.

Main modules description:
 - CommDevices : defines the main callback functions to communicate with mobile devices using the general library.
 - CommWebUsers : defines the main functions to handle the set of Web users.
 - Connect4 : defines the main functions to save the state of the Connect4 game.
 - DataBase : defines the DB structure.
 - Handlers :  defines the main function to handle the messages that comes from users (web or Android users).
 - Main : defines the Yesod app.

To try the example:
+ On an Android device, you follow these steps: [2].
+ Once you registered on Server, you can start playing against web or Android users. [1]

Every feedback is welcome!

[1] http://gsoc.marcospividori.com.ar/
[2] http://gsoc.marcospividori.com.ar/apps
[3] https://github.com/MarcosPividori/GSoC-Communicating-with-mobile-devices/tree/master/test
[4] http://www.windowsphone.com/es-ar/store/app/gsoc_example/1e4813bf-c72d-4c18-87f8-65a418433b50