feat(main.c file functions reorganized, assert function also done)

include/utils.h

+#if !defined(UTILS_H)
+#define UTILS_H
+
+#define NULL 0
+#define EXIT_SUCCESS 0
+#define assert(b) assert0((b), __FILE__, __FUNCTION__, __LINE__)
+
+void clear_screen();            /* clear screen */
+void putc(char aChar);          /* print a single char on screen */
+void puts(const char *aString); /* print a string on the screen */
+void puthex(int aNumber);       /* print an Hex number on screen */
+void assert0(char b, const char *filename, const char *fct_name, const int line);
+void irq_disable();
+void irq_enable();
+
+#endif // UTILS_H