Weak documentation on buffer-local hooks.

[Kim F. Storm]

Now that make-local-hook is obsoleted by the LOCAL arg to add-hook,
that function is no longer documented in the Emacs lisp manual.

Consequently, the documentation about buffer-local hooks is pretty
much non-existing in the manual now.  Specifically, the following
information should be included in the descriptive part of the Hooks
section (edited from the doc string of make-local-hook): 

Buffer-local hooks:

When a hook is added as a buffer-local hook, its local and global values
work in concert: running the hook actually runs all the hook
functions listed in *either* the local value *or* the global value
of the hook variable.


This should probably be added to add-hook's documentation:

This works by making t a member of the buffer-local value, which acts
as a flag to run the hook functions in the default value as well.


I'm not sure whether the following is still valid:

This works for all normal hooks, but does not work for most non-normal
hooks yet.  We will be changing the callers of non-normal hooks so
that they can handle localness; this has to be done one by one.


-- 
Kim F. Storm <address@hidden> http://www.cua.dk