New Command - SetGameSpeed

To use it, write in Maniacs TPC:
`@raw 2049, "", speedIsVar, speed`

e.g.:
`@raw 2049, "", 0,12`

The command must be inserted inside a parallel process, because `Game_Clock::SetGameSpeedFactor(speed);` only changes the speed at current frame.

Any refactor (to improve how it's called or to hide the speed counter) is welcome.

Author: jetrotal

src/game_interpreter.cpp

@@ -821,6 +821,8 @@ bool Game_Interpreter::ExecuteCommand(lcf::rpg::EventCommand const& com) {
 			return CommandManiacSetGameOption(com);
 		case Cmd::Maniac_CallCommand:
 			return CommandManiacCallCommand(com);
+		case static_cast<Game_Interpreter::Cmd>(2049) : //Cmd::Easy_SetGameSpeed
+			return CommandSetGameSpeed(com);
 		default:
 			return true;
 	}
@@ -4643,6 +4645,12 @@ bool Game_Interpreter::CommandManiacCallCommand(lcf::rpg::EventCommand const&) {
 	return true;
 }
 
+bool Game_Interpreter::CommandSetGameSpeed(lcf::rpg::EventCommand const& com) {
+	int32_t speed = ValueOrVariable(com.parameters[0], com.parameters[1]);
+	Game_Clock::SetGameSpeedFactor(speed);
+	return true;
+}
+
 Game_Interpreter& Game_Interpreter::GetForegroundInterpreter() {
 	return Game_Battle::IsBattleRunning()
 		? Game_Battle::GetInterpreter()

src/game_interpreter.h

@@ -284,6 +284,7 @@ class Game_Interpreter
 	bool CommandManiacChangePictureId(lcf::rpg::EventCommand const& com);
 	bool CommandManiacSetGameOption(lcf::rpg::EventCommand const& com);
 	bool CommandManiacCallCommand(lcf::rpg::EventCommand const& com);
+	bool CommandSetGameSpeed(lcf::rpg::EventCommand const& com);
 
 	int DecodeInt(lcf::DBArray<int32_t>::const_iterator& it);
 	const std::string DecodeString(lcf::DBArray<int32_t>::const_iterator& it);