Add json interface for sendsms

[m4r10k]

Its time to introduce a new interface because the sendsms URL get | post interface is really old and is only useful for backward compatibility. And of course it lacks a lot of useful features.

The new interface should make things easier and more informational. For telephone number validation we should use https://github.com/daviddrysdale/python-phonenumbers.

The structure of the send interface should be like:

{
  "targetnr": "+4312345678",
  "validate": true,
  "appid": "4dd658b4-6b86-11e5-9d70-feff819cdc9f",
  "prioriry": 2,
  "content": "This is the SMS content text"
}

The answer should be like:

{
  "status": 0,
  "description": "success",
  "smsid": "e007c7ea-6b86-11e5-9d70-feff819cdc9f"
}

[baccenfutter]

👍