Started to implement game switching.

I noticed that games that were not detected are not greyed out - that
needs to be fixed. Also, LOOT crashes immediately with no error if a
game is selected in the menu.
Fixed game switch crash and missing game switching.

Games that aren't detected get their menu items disabled so they can't
be switched to. Also rewrote the CEF init queries to use JS Promises to
ensure everything gets loaded when needed.

Game switching doesn't work properly yet though.
Game switching fixes.

* Recording game data works correctly.
* Global messages now get cleared from the UI.
* Fixed undefined variable error.