Reduce size of messages in Horizon / Godit

Reduce the size of messages.

Reduce the json at the minimum.

For example, change:

```
"pos": {
  "x": 7.8796,
  "y": 76754.67,
  "z": 0.1123,
}
```

with:
 
```
"pos": [7.8796, 76754.67, 0.1123]
}
```

perhaps replace not changed value by `null`

Encode the json message in binary, it will reduce between 5 to 10 times the size ;)
