ChangeEvent shape not well documented

First comment:

http://developer.couchbase.com/mobile/develop/references/couchbase-lite/couchbase-lite/database/database/index.html#string-change

In the Java Code, you can see the shape:

```
public static class ChangeEvent {

private Database source;
private boolean isExternal;
private List<DocumentChange> changes;

public ChangeEvent(Database source, boolean isExternal, List<DocumentChange> changes)

{ this.source = source; this.isExternal = isExternal; this.changes = changes; }

public Database getSource()

{ return source; }

public boolean isExternal()

{ return isExternal; }

public List<DocumentChange> getChanges()

{ return changes; }

}
```

see other comments: https://github.com/couchbaselabs/couchbase-mobile-portal/issues/155