Autocompletion: supporting self references

Hi,

Look like self references are not supported by the schema autocompletion feature. For example, on `self` key in the example below:
```
{
"type": "object",
"properties": {
"self": {
"$ref": "#"
},
"bar": {
"type": "string",
"enum": [
"A",
"B"
]
}
},
"additionalProperties": false
}
```