Simply XML schema for objects

Old  schema:

```javascript
t = {a: "3", "b": 3, "3": 3.0};
```
```xml
<program>
  <assign>
    <left>
      <identifier>t</identifier>
    </left>
    <operator>=</operator>
    <right>
      <object>
        <assign>
          <left>
            <identifier>a</identifier>
          </left>
          <operator>:</operator>
          <right>
            <string>3</string>
          </right>
        </assign>
        <assign>
          <left>
            <string>b</string>
          </left>
          <operator>:</operator>
          <right>
            <number>3</number>
          </right>
        </assign>
        <assign>
          <left>
            <string>3</string>
          </left>
          <operator>:</operator>
          <right>
            <number>3.0</number>
          </right>
        </assign>
      </object>
    </right>
  </assign>
</program>

```

New schema:

```xml
<program>
  <assign>
    <left>
      <identifier>t</identifier>
    </left>
    <operator>=</operator>
    <right>
      <object>
        <property name="a">
          <string>3</string>
        </property>
        <property name="b">
          <number>3</number>
        </property>
        <property name="3">
          <number>3.0</number>
        </property>
      </object>
    </right>
  </assign>
</program>
```