Make TriScriptedImporterEditor non-sealed

[yasirkula]

Currently my ScriptedImporterEditor's structure has to be as follows to support Tri-Inspector:

public class MyScriptedImporterEditor : ScriptedImporterEditor
{
    private TriEditorCore triEditor;

    public override void OnEnable()
    {
        base.OnEnable();
        triEditor = new TriEditorCore(this);
    }

    public override void OnDisable()
    {
        triEditor.Dispose();
        base.OnDisable();
    }

    public override void OnInspectorGUI()
    {
        triEditor.OnInspectorGUI();
        ApplyRevertGUI();
    }
}

However, I'd like to write it as follows instead:

public class MyScriptedImporterEditor : TriScriptedImporterEditor
{
}

To achieve this, perhaps another sealed class called TriScriptedImporterEditorFallback can be generated which has the [CustomEditor(typeof(ScriptedImporter), true)] attribute and that attribute can be removed from TriScriptedImporterEditor, allowing it to now be abstract:

[CanEditMultipleObjects]
[CustomEditor(typeof(ScriptedImporter), true)]
public sealed class TriScriptedImporterEditorFallback : TriScriptedImporterEditor
{
}

Note that this convenient inheritance is already available for TriEditor so for normal Editor implementations, I can simply inherit from TriEditor instead of Editor. I basically want the same convenience for TriScriptedImporterEditor.