So to unlock Mods on your Mac version of _Civ V_, you need to comment out line 33 of `MainMenu.lua`.  When Gods and Kings came out, `MainMenu.lua` moved, but the fix still worked.  Now that "Brave New World" is out, it appears `MainMenu.lua` has moved again or has just been removed entirely.

Where's `MainMenu.lua` so that I can perform some surgery on it?