Now this should be complete

Added basic shell and fixed various bugs...now iceos should be
"complete".

kernel/libc/stdio.h

@@ -14,6 +14,7 @@
 #include <stdarg.h>
 
 int printf(const char *format, ...);
+int printf_color(const char *format, uint8_t fg, uint8_t bg); // Only for string for now
 void puts(const char *buf);
 
 #endif