More updates to Programs chapter of Emacs manual.

More updates to Programs chapter of Emacs manual.

* doc/emacs/programs.texi (Man Page): Clarify how to use Man-switches.
Don't bother documenting Man-fontify-manpage-flag.
(Lisp Doc): Add xref to Name Help node.
(Hideshow): Add cindex.  Mention role of ellipses, and default
value of hs-isearch-open.  Don't bother documenting
hs-special-modes-alist.
(Symbol Completion): Add kindex for C-M-i.  Don't recommend
changing the window manager binding of M-TAB.