Delete many references to Emacs 23 or older from docs

Delete many references to Emacs 23 or older from docs

* doc/emacs/glossary.texi (Glossary):
* doc/emacs/msdos.texi (Windows Fonts):
* doc/lispref/loading.texi (Library Search):
* doc/lispref/processes.texi (Accepting Output):
* doc/misc/auth.texi (GnuPG and EasyPG Assistant Configuration):
* doc/misc/efaq-w32.texi (Font names):
* doc/misc/efaq.texi (Turning on syntax highlighting)
(Escape sequences in shell output):
* doc/misc/eshell.texi (Bugs and ideas):
* doc/misc/gnus.texi (nnmairix requirements):
* doc/misc/gnus-faq.texi (FAQ 1-5):
* doc/misc/idlwave.texi (Troubleshooting):
* doc/misc/message.texi (Using S/MIME):
* doc/misc/mh-e.texi (Preface, Incorporating Mail):
* doc/misc/viper.texi (Viper Specials): Delete references to Emacs 23
or older.