You don't need to dynamic_cast everywhere to check things anymore.
Folders can have metadata now (currently not set up).
Metadata is now a public member variable instead of a function that
returns a pointer to make actually using const possible.
Added GuiMsgBoxOk and GuiMsgBoxYesNo, basic message boxes.
Added rating scraping to TheGamesDB scraper.
Added warning if platform ID is not set for a system the user has selected
to scrape.