Add lock and group icon to scene tree editor
Fix crash in editor when open new scene in editing

resources_dock->cleanup(); // This will delete GDScript instance (if property_editor->obj is scene's GDScript instance, editor will crash)
Merge pull request #381 from marynate/PR-scene-tree-icons

Add lock and group icon to scene tree editor
Merge pull request #383 from sanikoyes/hotfix-Crash-In-Editor

Fix crash in editor when open new scene in editing
Make visibility icon always last to display in scene tree
Merge pull request #386 from marynate/PR-scene-tree-align-eye-icon

Make visibility icon always last to display in scene tree