Fire 'saveSnapshot' in setData.
Unified the way two callbacks are added in setData.
Introduce editable.status.
Check the status of editable in undo manager.
Do not change snapshots stack when editor is in mode difference than 'wysiwyg'.
Remove if !this.editor.mode, this is checking later.
Add status 'detached' to editable.
Set status 'ready' only if previous status was 'unloaded'.