apropos commands for commands, user options, all functions, all variables

[Stephen J. Turnbull]

Drew Adams writes:

 > Users should be able to find and use commands that give them info about (a)
 > all vars, (b) all functions, (c) just commands, and (d) just user options;
 > and the names of those commands should reflect what they do.

FWIW, XEmacs has had `C-h a' bound to `hyper-apropos' (dunno if this
exists in Emacs) which returns all variables and functions with
non-void values and function cells respectively, for a decade now,
with no complaints about verboseness that I can remember.

 > Similarly, we should rename `set-variable' to `set-option' and define a new
 > `set-variable' command that sets any variable, not just a user option. (I
 > have defined such a command in my own code, but I just call it
 > `set-any-variable', for now.)

Why not just make `setq' interactive?