Add message title for Google Cloud Messge (GCM)

[johnroyer]

iOS app does not support message title, but Android can.

I add message title in GooglePushService.php and change work flow in method send() to set title for Android message.

I've test on Sony mobile. May need some help testing on other devices.
Thanks

[nickygerritsen]

First of all, thanks!

I think it makes sense to have the AbstractPushService expose the setMessageTitle function and have the Apple Push Service throw an exception or even ignore the value completely.

So that you do not have to do that much runtime checking of the types.

[renefloor]

The library now supports 'title' and 'content' in stead of 'message'. There is not really a reason in Android to support only 2 types of data. It would be better to make this more flexibel so that users of the library can choose what to send and add for example an image url.

[johnroyer]

@nickygerritsen: I add definition in AbstractPushService.php and PushService.php. And throw RuntimeException when method called in ApplePushService.

Can you review this change for me? Thanks.

[johnroyer]

@renefloor: I know that GCM and APNS now support custom data / field. It is a lot of works to do before we support custom data into Push service. How about open a issue to figure out a better way ?

[renefloor]

@johnroyer I opened an issue so it won't be lost over time.