Merge separate RGSS version build configs into one

Setup active RGSS version at runtime. Desired version can be
specified via config, or as default, auto detected from the game
files. This removes the need to build specifically for each
version, which should help packaging a lot.

This also greatly reduces the danger of introducing code that
wouldn't compile on all RGSS version paths (as certain code paths
were completely ifdef'd out).

This can be optimized more, eg. not compiling shaders that aren't
needed in the active version.

src/sharedstate.cpp

@@ -46,15 +46,21 @@
 #include <string>
 
 SharedState *SharedState::instance = 0;
+int SharedState::rgssVersion = 0;
 static GlobalIBO *_globalIBO = 0;
 
-#ifdef RGSS3
-#define GAME_ARCHIVE "Game.rgss3a"
-#elif RGSS2
-#define GAME_ARCHIVE "Game.rgss2a"
-#else
-#define GAME_ARCHIVE "Game.rgssad"
-#endif
+static const char *defGameArchive()
+{
+	if (rgssVer == 1)
+		return "Game.rgssad";
+	else if (rgssVer == 2)
+		return "Game.rgss2a";
+	else if (rgssVer == 3)
+		return "Game.rgss3a";
+
+	assert(!"unreachable");
+	return 0;
+}
 
 struct SharedStatePrivate
 {
@@ -122,7 +128,7 @@ struct SharedStatePrivate
 		}
 
 		// FIXME find out correct archive filename
-		std::string archPath = GAME_ARCHIVE;
+		std::string archPath = defGameArchive();
 
 		/* Check if a game archive exists */
 		FILE *tmp = fopen(archPath.c_str(), "r");
@@ -158,8 +164,9 @@ struct SharedStatePrivate
 
 		/* RGSS3 games will call setup_midi, so there's
 		 * no need to do it on startup */
-#if MIDI && !RGSS3
-		midiState.initDefaultSynths();
+#if MIDI
+		if (rgssVer <= 2)
+			midiState.initDefaultSynths();
 #endif
 	}
 
@@ -177,6 +184,9 @@ void SharedState::initInstance(RGSSThreadData *threadData)
 	 * SharedState depends on GlobalIBO existing,
 	 * Font depends on SharedState existing */
 
+	rgssVersion = threadData->config.rgssVersion;
+	Font::initDefaults();
+
 	_globalIBO = new GlobalIBO();
 	_globalIBO->ensureSize(1);