This is a custom implementation of the 'printf' function which handles the following specifiers:
%s for printing strings. '%c' for printing characters. '%%' for printing a literal 'character'. '%d' and '%i'for printing signed integers.
- The custom 'printf' function print to standard output.
- It returns the total number of characters printed.
- it handles the specifiers '%d', '%c', '%i', '%s' and '%%'.
- It handles conversion of unsigned int to binary
- It handles the printing of strings in reverse
- It handles rot13'ed string