Runtime Version Scanner: Add the ability to delete pieces of content

[toph-allen]

#286 describes adding the capability to lock items in the Runtime Version Scanner. For very old content or outdated items, instead of locking them, the user might just want to delete them. We could give them this capability!

[jonkeane]

#286 describes adding the capability to lock items in the Runtime Version Scanner.

Does it? Maybe I'm missing something but I don't see it? Regardless, this seems like a good, quick win.