Two minor fixes:
- In EditorDesktop, I've wrapped frame.setVisible(true) with a SwingEDTUtils.invokeLater(Runnable runnable) call, as this is the way this should be done.
- I've fixed parity2's project.json file so it can be actually opened with the editor
Adding basic support for deleting scenes. This involved:
- Creating a CompositeCommand
- Creating a DeleteScene action
- Modification of view (MainBuilder, ScenesList, SidesLayout, TopBottomLayout, EditorGameView, LeftRightLayout) to make the contextual menu appear also after clicking on particular scenes and to make ScenesList layout adjust properly

Also, some minor fixes have been included as I occasionally found things to be fixed