install, rmdir: write --verbose output to stdout, not to stderr.

install, rmdir: write --verbose output to stdout, not to stderr.

* src/install.c (announce_mkdir): Write verbose output to stdout,
not to stderr.
* src/mkdir.c (announce mkdir): Use prog_fprintf for verbose output.
* src/prog-fprintf.c (prog_fprintf): New function and file.
* src/prog-fprintf.h: New file.
* src/rmdir.c (main): Write verbose output to stdout, not to stderr.
Quote directory name in a diagnostic.
* src/rmdir.c (remove_parents): Write verbose output to stdout,
not to stderr.
* doc/coreutils.texi: Mention that shred verbose output is to stderr.
* NEWS: Mention the changes.

Signed-off-by: Ondřej Vašík <ovasik@redhat.com>