externalise Push config

As we are adding more and more support for Push Networks (iOS, Android, Microsoft, firefoxOS, Amazon), the configuration list is getting longer and longer in the code. What about creating a separate json file containing this config that the plugin could consume ?

like, pushconfig.json :

{
pushServerURL: "https://javaoneups-sblanc.rhcloud.com/ag-push/",
android:

{ senderID: "313664704978", variantID: "39d64fb1-6c82-4638-9d02-3fbbbad5ba28", variantSecret: "d2e4e60a-e3d9-4db7-acee-0d18abc953a4" }

,
ios :

{ .... }

,
simplePush :

{ ... },
microsoft : { ... },
amazon : { ... }

}

That should not be mandatory as we could still use the "inline" style.