Drop jerry_port_putchar

Recent changes eliminate the need for `jerry_port_putchar`. As port
API discussions don't make it likely that it will ever be needed
again, this patch removes its declaration from jerry-port.h and its
implementations from the port(s).

The related code in jerry-libc is not needed either: whatever `putc`
(and `puts`) can do, `printf` can do as well.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

jerry-libc/include/stdio.h

@@ -48,7 +48,6 @@ extern FILE *stderr;
  * I/O routines
  */
 int vfprintf (FILE *stream, const char *format, va_list ap);
-int puts (const char *s);
 FILE *fopen (const char *path, const char *mode);
 int fclose (FILE *fp);
 size_t fread (void *ptr, size_t size, size_t nmemb, FILE *stream);
@@ -58,7 +57,6 @@ long ftell (FILE *stream);
 int printf (const char *format, ...);
 void rewind (FILE *stream);
 int fprintf (FILE *stream, const char *format, ...);
-int putchar (int c);
 
 #ifdef __cplusplus
 }