Update lua-engine.cpp

Added functionality for unloading a ROM. utilizing a function present in "window.cpp", a new Lua function was added to the emu API to allow Lua scripts to close out of games without having to close out of the whole emulator.

src/lua-engine.cpp

@@ -645,6 +645,13 @@ static int emu_insertOrEjectDisk(lua_State* L)
 	return 0;
 }
 
+// emu.closeRom()
+// Closes out of currently running ROM to allow user to switch games
+static int emu_closeRom(lua_State* L)
+{
+	CloseGame();
+	return 0;
+}
 
 // emu.loadrom(string filename)
 //
@@ -6089,6 +6096,7 @@ static const struct luaL_reg emulib [] = {
 	{"getdir", emu_getdir},
 	{"switchDisk", emu_switchDisk},
 	{"insertOrEjectDisk", emu_insertOrEjectDisk},
+	{"closeRom", emu_closeRom},
 	{"loadrom", emu_loadrom},
 	{"print", print}, // sure, why not
 	{"exit", emu_exit}, // useful for run-and-close scripts