* add scratchLogo as default for logo prop
* prefer `{featureAllowed && (<Component />)} over ternary operator with a null ‘else’
* renamed `handleSaveToComputer` as `getSaveToComputerHandler` to more clearly represent what it’s doing (returning a function to be the handler)
* renamed the parameter that is the function to handle clicking on the load project menu item (also updated the comments in `SBFileUploader`)

Show alternate logo if GUI is initialized with a different file.

Show or hide the language and file menus.

* removed commented out cruft
* added tabIndex prop to delete button (with default=0)
* the last change also required a change to the sprite selector test snapshot

Prototype of larger delete button for sprites, costumes and sounds to better support touch devices.

I split it out from `CloseButton` as it made the changes simpler, and we may end up going in a different direction (open context menu).