Add localization "foundation" (many code changes)

This commit adds most of the code changes necessary for making the game
translatable, but does not yet "unhardcode" nearly all of the strings
(except in a few cases where it was hard to separate added
loc::gettexts from foundational code changes, or all the localization-
related menus which were also added by this commit.)

This commit is part of rewritten history of the localization branch.
The original (unsquashed) commit history can be found here:
https://github.com/Dav999-v/VVVVVV/tree/localization-orig

desktop_version/src/main.cpp

@@ -16,6 +16,8 @@
 #include "Input.h"
 #include "InterimVersion.h"
 #include "KeyPoll.h"
+#include "Localization.h"
+#include "LocalizationStorage.h"
 #include "Logic.h"
 #include "Map.h"
 #include "Music.h"
@@ -368,6 +370,8 @@ int main(int argc, char *argv[])
 {
     char* baseDir = NULL;
     char* assetsPath = NULL;
+    char* langDir = NULL;
+    char* fontsDir = NULL;
     bool seed_use_sdl_getticks = false;
 #ifdef _WIN32
     bool open_console = false;
@@ -420,6 +424,20 @@ int main(int argc, char *argv[])
                 assetsPath = argv[i];
             })
         }
+        else if (ARG("-langdir"))
+        {
+            ARG_INNER({
+                i++;
+                langDir = argv[i];
+            })
+        }
+        else if (ARG("-fontsdir"))
+        {
+            ARG_INNER({
+                i++;
+                fontsDir = argv[i];
+            })
+        }
         else if (ARG("-playing") || ARG("-p"))
         {
             ARG_INNER({
@@ -482,6 +500,10 @@ int main(int argc, char *argv[])
         {
             vlog_toggle_error(0);
         }
+        else if (ARG("-translator"))
+        {
+            loc::show_translator_menu = true;
+        }
 #ifdef _WIN32
         else if (ARG("-console"))
         {
@@ -501,6 +523,10 @@ int main(int argc, char *argv[])
         }
     }
 
+#if defined(ALWAYS_SHOW_TRANSLATOR_MENU)
+    loc::show_translator_menu = true;
+#endif
+
 #ifdef _WIN32
     if (open_console)
     {
@@ -508,7 +534,7 @@ int main(int argc, char *argv[])
     }
 #endif
 
-    if(!FILESYSTEM_init(argv[0], baseDir, assetsPath))
+    if(!FILESYSTEM_init(argv[0], baseDir, assetsPath, langDir, fontsDir))
     {
         vlog_error("Unable to initialize filesystem!");
         VVV_exit(1);
@@ -608,12 +634,24 @@ int main(int argc, char *argv[])
         gameScreen.init(&screen_settings);
     }
 
+    loc::loadtext(false);
+    loc::loadlanguagelist();
+    game.createmenu(Menu::mainmenu);
+
     graphics.create_buffers(gameScreen.GetFormat());
 
     if (game.skipfakeload)
         game.gamestate = TITLEMODE;
     if (game.slowdown == 0) game.slowdown = 30;
 
+    if (!loc::lang_set)
+    {
+        game.gamestate = TITLEMODE;
+        game.menustart = true;
+        game.createmenu(Menu::language);
+        game.currentmenuoption = loc::languagelist_curlang;
+    }
+
     //Check to see if you've already unlocked some achievements here from before the update
     if (game.swnbestrank > 0){
         if(game.swnbestrank >= 1) game.unlockAchievement("vvvvvvsupgrav5");
@@ -757,6 +795,7 @@ static void cleanup(void)
     music.destroy();
     map.destroy();
     NETWORK_shutdown();
+    loc::resettext(true);
     SDL_Quit();
     FILESYSTEM_deinit();
 }