[lib:stdio] Add fclose(), fopen() and freopen()
[lib:stdio] Add fputs() and puts()
[lib:stdio] Add fputs(), puts() and putchar()
[lib:stdio] Add fgets()

- Never use gets()
[lib:stdio] Add fgetc(), getc() and getchar()
[lib:stdio] Add ungetc()
[libc:stdio] Add feof(), ferror() and clearerr()
[lib:stdio] Add setvbuf() and setbuf()