[debug] add support for mgba printf

* adds support for mgba printf debugging as well as adding support for switching between debugging configuration
* adds `mini_printf` as an alternative to libc printf as well as switches to choose a pretty printing handler
* adds a pretty printing format to `mini_printf` to print preproc encoded strings

src/main.c

@@ -119,6 +119,13 @@ void AgbMain()
     gLinkTransferringData = FALSE;
     sUnusedVar = 0xFC0;
 
+#ifndef NDEBUG
+#if (LOG_HANDLER == LOG_HANDLER_MGBA_PRINT)
+    (void) MgbaOpen();
+#elif (LOG_HANDLER == LOG_HANDLER_AGB_PRINT)
+    AGBPrintfInit();
+#endif
+#endif
     for (;;)
     {
         ReadKeys();