Add PNG connection type and Freetype 2 font rendering to glcd driver. The PNG

image writer is for debugging only. The Freetype font renderer still misses
some features (e.g. big numbers, character encoding, non-standard cell size).

server/drivers/glcd-png.h

@@ -0,0 +1,8 @@
+#ifndef GLCD_PNG_H
+#define GLCD_PNG_H
+
+int glcd_png_init(Driver *drvthis);
+void glcd_png_blit(PrivateData *p);
+void glcd_png_close(PrivateData *p);
+
+#endif