include stb_connected_components.h in main stb compile tests, add test app

tests/test_truetype.c

@@ -3,13 +3,13 @@
 #include "stb_truetype.h"
 #include "stb_image_write.h"
 
+#ifdef TT_TEST
+
 #include <stdio.h>
 
 char ttf_buffer[1<<25];
 unsigned char output[512*100];
 
-#ifdef TT_TEST
-
 void debug(void)
 {
    stbtt_fontinfo font;