Add send message func to send a pure json payload

Add a new func in gateway server, so we can use a pure json payload instead of
using Payload object to build a payload

	modified:   apns.py
Change apns api to V2

Use the V2 apns api, add apns response check

	modified:   apns.py
Add callback to **connect()**  method

	modified:   apns.py
Modify the apns-send to V2

1. modify send_notifition() to API V2
2. modify apns-send to new method
Merge branch 'dev-payload-json' into dev

Conflicts:

	apns.py